dev-lang/rust{,-bin}: port to llvm-r1 and slot (-r100)

Port to llvm-r1 to gain the fancy new `llvm_slot_{x}` USE flags
which we use in the rust eclass to force a closer dependency on
specific LLVM slots.

Since Rust in Gentoo is only ever built against the one LLVM slot
we are able to simplify the LLVM logic in the Rust ebuilds and use
our knowledge of the LLVM -> Rust version mapping to enable
slots for dev-lang/rust in a usable manner.

Since Rust is now slotted and not managed entirely by eselect-rust
each slot needs to be added to LDPATH.

We also drop the `profiler` USE as it's inconsistent with what
upstream ship by default and casues issues where other package's
build systems assume that it exists.

This commit also introduces dev-lang/rust-common which handles bash
completions for slotted Rust.

dev-lang/rust-bin:

`LLVM_OPTIONAL` is used as we don't need to consume LLVM,
we really just want the free IUSE.

Closes: https://bugs.gentoo.org/941146
Signed-off-by: Matt Jolly <kangie@gentoo.org>

20 files changed, 8230 insertions, 0 deletions

diff --git a/dev-lang/rust-bin/rust-bin-1.71.1-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.71.1-r100.ebuild
new file mode 100644
index 000000000000..1c40bfad383f
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.71.1-r100.ebuild
@@ -0,0 +1,232 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 16 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2023-08-03/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~sam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz -> ${MY_P}-sparc64-unknown-linux-gnu.sam.tar.xz ) "
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4 UoI-NCSA"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}/bin/bash")
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.74.1-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.74.1-r100.ebuild
new file mode 100644
index 000000000000..c439536ef6bd
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.74.1-r100.ebuild
@@ -0,0 +1,242 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2023-12-07/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~sam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+#SRC_URI+=" mips? (
+#	abi_mips_o32? (
+#		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+#		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+#	)
+#	abi_mips_n64? (
+#		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+#		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+#	)
+#)"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}/bin/bash")
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.75.0-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.75.0-r100.ebuild
new file mode 100644
index 000000000000..10b3ef1a7932
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.75.0-r100.ebuild
@@ -0,0 +1,242 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2023-12-28/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~sam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+#SRC_URI+=" mips? (
+#	abi_mips_o32? (
+#		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+#		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+#	)
+#	abi_mips_n64? (
+#		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+#		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+#	)
+#)"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}"/bin/bash)
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.77.1-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.77.1-r100.ebuild
new file mode 100644
index 000000000000..c973e8b738de
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.77.1-r100.ebuild
@@ -0,0 +1,244 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2024-03-28/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~arthurzam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+SRC_URI+=" mips? (
+	abi_mips_o32? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+	)
+	abi_mips_n64? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+	)
+)"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,rust-demangler-preview,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}"/bin/bash)
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-demangler
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-demangler
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.79.0-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.79.0-r100.ebuild
new file mode 100644
index 000000000000..1aac4008cb46
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.79.0-r100.ebuild
@@ -0,0 +1,247 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2024-06-13/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~arthurzam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+SRC_URI+=" mips? (
+	abi_mips_o32? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+	)
+	abi_mips_n64? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+	)
+)"
+SRC_URI+=" riscv? (
+	elibc_musl? ( ${GENTOO_BIN_BASEURI}/${MY_P}-riscv64gc-unknown-linux-musl.tar.xz )
+)"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so*
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,rust-demangler-preview,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}"/bin/bash)
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-demangler
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-demangler
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.80.1-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.80.1-r100.ebuild
new file mode 100644
index 000000000000..3e8c9a394475
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.80.1-r100.ebuild
@@ -0,0 +1,251 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2024-08-08/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~arthurzam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+SRC_URI+=" mips? (
+	abi_mips_o32? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+	)
+	abi_mips_n64? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+	)
+)"
+SRC_URI+=" riscv? (
+	elibc_musl? ( ${GENTOO_BIN_BASEURI}/${MY_P}-riscv64gc-unknown-linux-musl.tar.xz )
+)"
+SRC_URI+=" ppc64? ( elibc_musl? (
+	big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-powerpc64-unknown-linux-musl.tar.xz )
+	!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-powerpc64le-unknown-linux-musl.tar.xz )
+) )"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so*
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,rust-demangler-preview,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}"/bin/bash)
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-demangler
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-demangler
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.81.0-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.81.0-r100.ebuild
new file mode 100644
index 000000000000..b5f1ce54ec05
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.81.0-r100.ebuild
@@ -0,0 +1,249 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal optfeature
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2024-09-05/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~arthurzam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+SRC_URI+=" mips? (
+	abi_mips_o32? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+	)
+	abi_mips_n64? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+	)
+)"
+SRC_URI+=" riscv? (
+	elibc_musl? ( ${GENTOO_BIN_BASEURI}/${MY_P}-riscv64gc-unknown-linux-musl.tar.xz )
+)"
+SRC_URI+=" ppc64? ( elibc_musl? (
+	big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-powerpc64-unknown-linux-musl.tar.xz )
+	!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-powerpc64le-unknown-linux-musl.tar.xz )
+) )"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv ~s390 sparc x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so*
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}"/bin/bash)
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-bin/rust-bin-1.82.0-r100.ebuild b/dev-lang/rust-bin/rust-bin-1.82.0-r100.ebuild
new file mode 100644
index 000000000000..4dbbd8d3be47
--- /dev/null
+++ b/dev-lang/rust-bin/rust-bin-1.82.0-r100.ebuild
@@ -0,0 +1,251 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+LLVM_OPTIONAL="yes"
+
+inherit llvm-r1 multilib prefix rust-toolchain toolchain-funcs verify-sig multilib-minimal optfeature
+
+MY_P="rust-${PV}"
+# curl -L static.rust-lang.org/dist/channel-rust-${PV}.toml 2>/dev/null | grep "xz_url.*rust-src"
+MY_SRC_URI="${RUST_TOOLCHAIN_BASEURL%/}/2024-10-17/rust-src-${PV}.tar.xz"
+GENTOO_BIN_BASEURI="https://dev.gentoo.org/~arthurzam/distfiles/${CATEGORY}/${PN}" # omit leading slash
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+SRC_URI="$(rust_all_arch_uris ${MY_P})
+	rust-src? ( ${MY_SRC_URI} )
+"
+# Keep this separate to allow easy commenting out if not yet built
+SRC_URI+=" sparc? ( ${GENTOO_BIN_BASEURI}/${MY_P}-sparc64-unknown-linux-gnu.tar.xz ) "
+SRC_URI+=" mips? (
+	abi_mips_o32? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips-unknown-linux-gnu.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mipsel-unknown-linux-gnu.tar.xz )
+	)
+	abi_mips_n64? (
+		big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64-unknown-linux-gnuabi64.tar.xz )
+		!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-mips64el-unknown-linux-gnuabi64.tar.xz )
+	)
+)"
+SRC_URI+=" riscv? (
+	elibc_musl? ( ${GENTOO_BIN_BASEURI}/${MY_P}-riscv64gc-unknown-linux-musl.tar.xz )
+)"
+SRC_URI+=" ppc64? ( elibc_musl? (
+	big-endian?  ( ${GENTOO_BIN_BASEURI}/${MY_P}-powerpc64-unknown-linux-musl.tar.xz )
+	!big-endian? ( ${GENTOO_BIN_BASEURI}/${MY_P}-powerpc64le-unknown-linux-musl.tar.xz )
+) )"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86"
+IUSE="big-endian clippy cpu_flags_x86_sse2 doc prefix rust-analyzer rust-src rustfmt"
+
+RDEPEND="
+	>=app-eselect/eselect-rust-20190311
+	dev-libs/openssl
+	sys-apps/lsb-release
+	sys-devel/gcc:*
+	!dev-lang/rust-bin:stable
+"
+
+BDEPEND="
+	prefix? ( dev-util/patchelf )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+REQUIRED_USE="x86? ( cpu_flags_x86_sse2 )"
+
+# stripping rust may break it (at least on x86_64)
+# https://github.com/rust-lang/rust/issues/112286
+RESTRICT="strip"
+
+QA_PREBUILT="
+	opt/${P}/bin/.*
+	opt/${P}/lib/.*.so*
+	opt/${P}/libexec/.*
+	opt/${P}/lib/rustlib/.*/bin/.*
+	opt/${P}/lib/rustlib/.*/lib/.*
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="opt/${P}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+VERIFY_SIG_OPENPGP_KEY_PATH="/usr/share/openpgp-keys/rust.asc"
+
+pkg_pretend() {
+	if [[ "$(tc-is-softfloat)" != "no" ]] && [[ ${CHOST} == armv7* ]]; then
+		die "${CHOST} is not supported by upstream Rust. You must use a hard float version."
+	fi
+}
+
+src_unpack() {
+	# sadly rust-src tarball does not have corresponding .asc file
+	# so do partial verification
+	if use verify-sig; then
+		for f in ${A}; do
+			if [[ -f ${DISTDIR}/${f}.asc ]]; then
+				verify-sig_verify_detached "${DISTDIR}/${f}" "${DISTDIR}/${f}.asc"
+			fi
+		done
+	fi
+
+	default_src_unpack
+
+	mv "${WORKDIR}/${MY_P}-$(rust_abi)" "${S}" || die
+}
+
+patchelf_for_bin() {
+	local filetype=$(file -b ${1})
+	if [[ ${filetype} == *ELF*interpreter* ]]; then
+		einfo "${1}'s interpreter changed"
+		patchelf ${1} --set-interpreter ${2} || die
+	elif [[ ${filetype} == *script* ]]; then
+		hprefixify ${1}
+	fi
+}
+
+multilib_src_install() {
+	if multilib_is_native_abi; then
+
+	# start native abi install
+	pushd "${S}" >/dev/null || die
+	local analysis std
+	analysis="$(grep 'analysis' ./components)"
+	std="$(grep 'std' ./components)"
+	local components="rustc,cargo,${std}"
+	use doc && components="${components},rust-docs"
+	use clippy && components="${components},clippy-preview"
+	use rustfmt && components="${components},rustfmt-preview"
+	use rust-analyzer && components="${components},rust-analyzer-preview,${analysis}"
+	# Rust component 'rust-src' is extracted from separate archive
+	if use rust-src; then
+		einfo "Combining rust and rust-src installers"
+		mv -v "${WORKDIR}/rust-src-${PV}/rust-src" "${S}" || die
+		echo rust-src >> ./components || die
+		components="${components},rust-src"
+	fi
+	./install.sh \
+		--components="${components}" \
+		--disable-verify \
+		--prefix="${ED}/opt/${P}" \
+		--mandir="${ED}/opt/${P}/man" \
+		--disable-ldconfig \
+		|| die
+
+	docompress /opt/${P}/man/
+
+	if use prefix; then
+		local interpreter=$(patchelf --print-interpreter "${EPREFIX}"/bin/bash)
+		ebegin "Changing interpreter to ${interpreter} for Gentoo prefix at ${ED}/opt/${P}/bin"
+		find "${ED}/opt/${P}/bin" -type f -print0 | \
+			while IFS=  read -r -d '' filename; do
+				patchelf_for_bin ${filename} ${interpreter} \; || die
+			done
+		eend $?
+	fi
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /opt/rust-bin-<ver>/bin/rustc-<ver>
+		local ver_i="${i}-bin-${PV}"
+		ln -v "${ED}/opt/${P}/bin/${i}" "${ED}/opt/${P}/bin/${ver_i}" || die
+		dosym "../../opt/${P}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "../../../opt/${P}/lib" "/usr/lib/rust/lib-bin-${PV}"
+	dosym "../../../opt/${P}/man" "/usr/lib/rust/man-bin-${PV}"
+	dosym "../../opt/${P}/lib/rustlib" "/usr/lib/rustlib-bin-${PV}"
+	dosym "../../../opt/${P}/share/doc/rust" "/usr/share/doc/${P}"
+
+	# make all capital underscored variable
+	local CARGO_TRIPLET="$(rust_abi)"
+	CARGO_TRIPLET="${CARGO_TRIPLET//-/_}"
+	CARGO_TRIPLET="${CARGO_TRIPLET^^}"
+	cat <<-_EOF_ > "${T}/50${P}"
+	LDPATH="${EPREFIX}/usr/lib/rust/lib-bin-${PV}"
+	MANPATH="${EPREFIX}/usr/lib/rust/man-bin-${PV}"
+	$(usev elibc_musl "CARGO_TARGET_${CARGO_TRIPLET}_RUSTFLAGS=\"-C target-feature=-crt-static\"")
+	_EOF_
+	doenvd "${T}/50${P}"
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+	/usr/bin/cargo
+	/usr/bin/rustdoc
+	/usr/bin/rust-gdb
+	/usr/bin/rust-gdbgui
+	/usr/bin/rust-lldb
+	/usr/lib/rustlib
+	/usr/lib/rust/lib
+	/usr/lib/rust/man
+	/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+	popd >/dev/null || die
+	#end native abi install
+
+	else
+		local rust_target
+		rust_target="$(rust_abi $(get_abi_CHOST ${v##*.}))"
+		dodir "/opt/${P}/lib/rustlib"
+		cp -vr "${WORKDIR}/rust-${PV}-${rust_target}/rust-std-${rust_target}/lib/rustlib/${rust_target}"\
+			"${ED}/opt/${P}/lib/rustlib" || die
+	fi
+
+	# BUG: installs x86_64 binary on other arches
+	rm -f "${ED}/opt/${P}/lib/rustlib/"*/bin/rust-llvm-dwp || die
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	elog "Rust installs a helper script for calling GDB now,"
+	elog "for your convenience it is installed under /usr/bin/rust-gdb-bin-${PV}."
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust-common/Manifest b/dev-lang/rust-common/Manifest
new file mode 100644
index 000000000000..88ff26dbed31
--- /dev/null
+++ b/dev-lang/rust-common/Manifest
@@ -0,0 +1,4 @@
+DIST rustc-1.81.0-src.tar.xz 216743872 BLAKE2B d9f52da9092d0723c862ebbb2dc351cad0670be6872f691b4c9f36faf06803f072720ebd04f06745c355d807991b38312cc830b12d6d3f50b0574bb7325340b7 SHA512 b8a837ced521d2ca2c7f228a0640da591384519e4dbc1ae768524d50616da6abbd2f7bdae3777caebc0447dac91bf76481282ce5a2264d7f30e173caa6321a51
+DIST rustc-1.81.0-src.tar.xz.asc 801 BLAKE2B 01cd9f386d3fd73f4eb43b14d7d479ebababb8640abbff170e697817b94b8a18edd801c6047ecf3c084a0a51764c5e4f3f4bd6b00e8ae000ef0b850e9506572a SHA512 19c0da9d67f2bd9fd79a2078f0f486ee7fad5646a09a609b7e30d9531851955ae8df0ec69f9ddc09e2fd6e74d529648335b0fda833839c88c54c84494ec1988e
+DIST rustc-1.82.0-src.tar.xz 219769328 BLAKE2B 611f33e134c2d459c9af1695c0a4d033df93afc986e91a17fceb0dd293fb4ffbd5f7475ef571d36cecf49da6c3fdb3801c98d7f72f9dd1c39e42502f649b192f SHA512 d158c7c71c1814bde2a3ec3cbeabe34949bd3201b730c0d7ec6baad4158bb28dd13696c430a6b99dc38b9d23ad7ddf8dde7d2487cbfbbbe9c3473016994210f0
+DIST rustc-1.82.0-src.tar.xz.asc 801 BLAKE2B 8138fb15b8d7ec15be45378fe663207a8e87e3c527348ab079995b1840a771ed6e9d5464eb8855ac9e006c0cfcf54b1a4fea489d31e6c9899cb03e6f4c737b67 SHA512 3cd6b27e72041baf9996efa10f25aca2e04f3e3727b60ecfd90c1bef9c52d216d2dc130802f935b110e35766645a27637a01661aa8d5acf02bf64b02a107c93c
diff --git a/dev-lang/rust-common/metadata.xml b/dev-lang/rust-common/metadata.xml
new file mode 100644
index 000000000000..b5c189c5f9b0
--- /dev/null
+++ b/dev-lang/rust-common/metadata.xml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
+<pkgmetadata>
+	<maintainer type="project">
+		<email>rust@gentoo.org</email>
+		<name>Rust Project</name>
+	</maintainer>
+	<upstream>
+		<remote-id type="github">rust-lang/rust</remote-id>
+	</upstream>
+</pkgmetadata>
diff --git a/dev-lang/rust-common/rust-common-1.81.0.ebuild b/dev-lang/rust-common/rust-common-1.81.0.ebuild
new file mode 100644
index 000000000000..fadef8ec46b5
--- /dev/null
+++ b/dev-lang/rust-common/rust-common-1.81.0.ebuild
@@ -0,0 +1,53 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit bash-completion-r1
+
+DESCRIPTION="Common files shared between multiple slots of Rust"
+HOMEPAGE="https://www.rust-lang.org/"
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	ABI_VER="$(ver_cut 1-2)"
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+fi
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT=0
+KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv sparc x86"
+IUSE="verify-sig"
+
+RDEPEND="
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+src_configure() {
+	:
+}
+
+src_compile() {
+	:
+}
+
+src_install() {
+	newbashcomp src/tools/cargo/src/etc/cargo.bashcomp.sh cargo
+}
diff --git a/dev-lang/rust-common/rust-common-1.82.0.ebuild b/dev-lang/rust-common/rust-common-1.82.0.ebuild
new file mode 100644
index 000000000000..c1d6b791917f
--- /dev/null
+++ b/dev-lang/rust-common/rust-common-1.82.0.ebuild
@@ -0,0 +1,54 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit bash-completion-r1
+
+DESCRIPTION="Common files shared between multiple slots of Rust"
+HOMEPAGE="https://www.rust-lang.org/"
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	ABI_VER="$(ver_cut 1-2)"
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+fi
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT=0
+KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+IUSE="verify-sig"
+
+# Legacy non-slotted versions bash completions will collide.
+RDEPEND="
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+src_configure() {
+	:
+}
+
+src_compile() {
+	:
+}
+
+src_install() {
+	newbashcomp src/tools/cargo/src/etc/cargo.bashcomp.sh cargo
+}
diff --git a/dev-lang/rust/rust-1.71.1-r100.ebuild b/dev-lang/rust/rust-1.71.1-r100.ebuild
new file mode 100644
index 000000000000..abec1d3edea7
--- /dev/null
+++ b/dev-lang/rust/rust-1.71.1-r100.ebuild
@@ -0,0 +1,734 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 16 )
+PYTHON_COMPAT=( python3_{10..12} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv sparc x86"
+fi
+
+S="${WORKDIR}/${MY_P}-src"
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARM AVR BPF Hexagon Lanai LoongArch Mips MSP430
+	NVPTX PowerPC RISCV Sparc SystemZ VE WebAssembly X86 XCore )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4 UoI-NCSA"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind +lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.71.1-fix-bootstrap-version-comparison.patch
+	"${FILESDIR}"/1.70.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.62.1-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+)
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi)"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/wasm_base.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		CMAKE_C_FLAGS_${cm_btype} = "${CFLAGS}"
+		CMAKE_CXX_FLAGS_${cm_btype} = "${CXXFLAGS}"
+		CMAKE_EXE_LINKER_FLAGS_${cm_btype} = "${LDFLAGS}"
+		CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = "${LDFLAGS}"
+		CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = "${LDFLAGS}"
+		CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = "${ARFLAGS}"
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_target}"
+		host = ["${rust_target}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		default-linker = "$(tc-getCC)"
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		lto = "$(usex lto fat off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.74.1-r100.ebuild b/dev-lang/rust/rust-1.74.1-r100.ebuild
new file mode 100644
index 000000000000..48efa65873f4
--- /dev/null
+++ b/dev-lang/rust/rust-1.74.1-r100.ebuild
@@ -0,0 +1,770 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{10..12} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv sparc x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+
+S="${WORKDIR}/${MY_P}-src"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind +lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.70.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.62.1-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/wasm_base.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		lto = "$(usex lto fat off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.75.0-r100.ebuild b/dev-lang/rust/rust-1.75.0-r100.ebuild
new file mode 100644
index 000000000000..d0154a05fc14
--- /dev/null
+++ b/dev-lang/rust/rust-1.75.0-r100.ebuild
@@ -0,0 +1,773 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{10..12} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv sparc x86"
+fi
+
+S="${WORKDIR}/${MY_P}-src"
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Language empowering everyone to build reliable and efficient software"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind +lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.75.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.70.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	# This patch shouldn't be necessary for later versions of Rust because its
+	# code was backported from master.
+	"${FILESDIR}"/1.75.0-handle-vendored-sources.patch
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		lto = "$(usex lto fat off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.77.1-r100.ebuild b/dev-lang/rust/rust-1.77.1-r100.ebuild
new file mode 100644
index 000000000000..0088c87f6631
--- /dev/null
+++ b/dev-lang/rust/rust-1.77.1-r100.ebuild
@@ -0,0 +1,771 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 17 )
+PYTHON_COMPAT=( python3_{10..12} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ppc ppc64 ~riscv sparc x86"
+fi
+S="${WORKDIR}/${MY_P}-src"
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.75.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.70.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	"${FILESDIR}"/1.76.0-loong-code-model.patch  # remove for >=1.78.0
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.79.0-r100.ebuild b/dev-lang/rust/rust-1.79.0-r100.ebuild
new file mode 100644
index 000000000000..d33958ee42ba
--- /dev/null
+++ b/dev-lang/rust/rust-1.79.0-r100.ebuild
@@ -0,0 +1,774 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{10..13} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv sparc x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.78.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.78.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	"${FILESDIR}"/1.79.0-revert-8c40426.patch
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc", "rust-demangler"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.80.1-r100.ebuild b/dev-lang/rust/rust-1.80.1-r100.ebuild
new file mode 100644
index 000000000000..3ae140bf6924
--- /dev/null
+++ b/dev-lang/rust/rust-1.80.1-r100.ebuild
@@ -0,0 +1,773 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{10..13} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv sparc x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.78.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	"${FILESDIR}"/1.79.0-revert-8c40426.patch
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+		rust-demangler
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-demangler
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.81.0-r100.ebuild b/dev-lang/rust/rust-1.81.0-r100.ebuild
new file mode 100644
index 000000000000..a8b946c44d66
--- /dev/null
+++ b/dev-lang/rust/rust-1.81.0-r100.ebuild
@@ -0,0 +1,774 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 18 )
+PYTHON_COMPAT=( python3_{10..13} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="amd64 arm arm64 ~loong ~mips ppc ppc64 ~riscv sparc x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).1"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.78.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	"${FILESDIR}"/1.79.0-revert-8c40426.patch
+	"${FILESDIR}/1.81.0-backport-bug937164.patch"
+	"${FILESDIR}/1.81.0-backport-llvm-pr101761.patch"
+	"${FILESDIR}/1.81.0-backport-llvm-pr101766.patch"
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}
diff --git a/dev-lang/rust/rust-1.82.0-r100.ebuild b/dev-lang/rust/rust-1.82.0-r100.ebuild
new file mode 100644
index 000000000000..fd370bf6309e
--- /dev/null
+++ b/dev-lang/rust/rust-1.82.0-r100.ebuild
@@ -0,0 +1,781 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LLVM_COMPAT=( 19 )
+PYTHON_COMPAT=( python3_{10..13} )
+
+inherit check-reqs estack flag-o-matic llvm-r1 multiprocessing optfeature \
+	multilib multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-src.tar.xz"
+else
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="~amd64 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).0"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+SLOT="${PV}"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+LLVM_DEPEND=()
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+for _x in "${ALL_LLVM_TARGETS[@]}"; do
+	LLVM_DEPEND+=( "	${_x}? ( $(llvm_gen_dep "sys-devel/llvm:\${LLVM_SLOT}[${_x}]") )" )
+done
+LLVM_DEPEND+=( "	wasm? ( $(llvm_gen_dep 'sys-devel/lld:${LLVM_SLOT}') )" )
+LLVM_DEPEND+=( "	$(llvm_gen_dep 'sys-devel/llvm:${LLVM_SLOT}')" )
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		>=dev-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	dev-lang/rust-common
+	sys-apps/lsb-release
+	!dev-lang/rust:stable/1.71.1
+	!dev-lang/rust:stable/1.74.1
+	!dev-lang/rust:stable/1.75.0
+	!dev-lang/rust:stable/1.77.1
+	!dev-lang/rust:stable/1.79.0
+	!dev-lang/rust:stable/1.80.1
+	!dev-lang/rust:stable/1.81.0
+	!dev-lang/rust:stable/1.82.0
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/libexec/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.78.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	"${FILESDIR}"/1.79.0-revert-8c40426.patch
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief --root="${BROOT}" rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm-r1_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	# Rust baselines to Pentium4 on x86, this patch lowers the baseline to i586 when sse2 is not set.
+	if use x86; then
+		if ! use cpu_flags_x86_sse2; then
+			eapply "${FILESDIR}/1.82.0-i586-baseline.patch"
+			grep -rl cmd.args.push\(\"-march=i686\" . | xargs sed  -i 's/march=i686/-march=i586/g' || die
+		fi
+	fi
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets+=",\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = true
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_EOF_
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then # whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix)/bin/llvm-config"
+			_EOF_
+		fi
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_EOF_
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="\"${RUSTFLAGS}\""
+	echo RUSTFLAGS_BOOTSTRAP="\"${RUSTFLAGS_BOOTSTRAP}\""
+	echo RUSTFLAGS_NOT_BOOTSTRAP="\"${RUSTFLAGS_NOT_BOOTSTRAP}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! RUST_BACKTRACE=1 "${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${D}" "${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+
+	docompress /usr/lib/${PN}/${PV}/share/man/
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/libexec" "/usr/lib/${PN}/libexec-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib-${PV}"
+		MANPATH="${EPREFIX}/usr/lib/rust/man-${PV}"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	if has_version app-editors/emacs; then
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}