-$PERL common/scripts/fix-gnulib.pl -o lib/gnulib.mk -i lib/gnulib.mk.in \
- || die "Failed to fixup Gnulib makefile fragment."
+$PERL common/scripts/fix-gnulib.pl -o lib/gnulib.mk -i lib/gnulib.mk.in ||
+ die "Failed to fixup Gnulib makefile fragment."
+
+# Rewrite if ! ... construts produced by gnulib conditional dependencies
+# as these fail in heirloom-sh.
+sed 's/if ! *\(.*gnulib_enabled[^;]*\); then/if \1; then :; else/' \
+ m4/gnulib-comp.m4 >m4/gnulib-comp.m4.new || exit
+mv -f m4/gnulib-comp.m4.new m4/gnulib-comp.m4 || exit