https://bugs.gentoo.org/show_bug.cgi?id=424137
https://savannah.gnu.org/bugs/?37558
https://code.google.com/p/original-mawk/issues/detail?id=17
--- grub-core/Makefile.am	2012-07-07 12:29:01 +0000
+++ grub-core/Makefile.am	2012-10-12 13:04:02 +0000
@@ -349,7 +349,7 @@
 
 # generate global module dependencies list
 moddep.lst: syminfo.lst genmoddep.awk video.lst
-	cat $< | sort | awk -f $(srcdir)/genmoddep.awk > $@ || (rm -f $@; exit 1)
+	cat $< | sort | $(AWK) -f $(srcdir)/genmoddep.awk > $@ || (rm -f $@; exit 1)
 platform_DATA += moddep.lst
 CLEANFILES += config.log syminfo.lst moddep.lst