bind sets up BUILD_XXX vars for building native tools, but then
doesn't use them for the "gen" tool

--- a/bind/lib/export/dns/Makefile.in
+++ b/bind/lib/export/dns/Makefile.in
@@ -166,7 +166,7 @@
 	./gen -s ${srcdir} > code.h
 
 gen: ${srcdir}/gen.c
-	${CC} ${ALL_CFLAGS} ${LDFLAGS} -o $@ ${srcdir}/gen.c ${LIBS}
+	${BUILD_CC} ${BUILD_CFLAGS} ${CINCLUDES} ${BUILD_LDFLAGS} -o $@ ${srcdir}/gen.c ${BUILD_LIBS}
 
 #We don't need rbtdb64 for this library
 #rbtdb64.@O@: rbtdb.c