http://bugs.gentoo.org/194216
Texinfo source is already shipped, so separate preparation not needed
and error-prone

--- docs/Makefile.in	2007-10-30 20:35:47.000000000 +0100
+++ docs/Makefile.in	2007-10-30 21:57:52.000000000 +0100
@@ -348,16 +348,6 @@
 gnuplot.info: $(srcdir)/gnuplot.texi
 	$(MAKEINFO) -I$(srcdir) $(srcdir)/gnuplot.texi --no-split --output=$@
 
-# Thanks to Bruce Ravel for doc2texi.el!
-$(srcdir)/gnuplot.texi: $(srcdir)/doc2texi.el $(srcdir)/gnuplot.doc
-	@echo "Creating texinfo"
-	@if test "$(EMACS)" != no; then \
-	   cd $(srcdir) ;  \
-	   $(EMACS) -batch -l doc2texi.el -f d2t-doc-to-texi ; \
-	else \
-	   echo "No emacs found - cannot create texinfo file" ; \
-	fi
-
 # this is how to make OS/2 ipfc documentation
 ipf: gnuplot.ipf