dash only supports single-digit fd redirects

Makefile.rules

@@ -77,13 +77,13 @@ cmd_CC+=$(CC_MKDEP_OPTS)
 cmd_MKDEP=
 endif # CC_MKDEP_OPTS
 
-cmd_CC_lock=while true; do ( flock -n 95 || exit 95; test -e $@ && exit 0; \
+cmd_CC_lock=while true; do ( flock -n 9 || exit 95; test -e $@ && exit 0; \
 	$(cmd_CC); \
-	) 95> $@.lock; exitcode=$$?; test $$exitcode = 95 || break; sleep 1; done; \
+	) 9> $@.lock; exitcode=$$?; test $$exitcode = 95 || break; sleep 1; done; \
 	rm -f $@.lock; exit $$exitcode
-cmd_LD_lock=while true; do ( flock -n 95 || exit 95; test -e $@ && exit 0; \
+cmd_LD_lock=while true; do ( flock -n 9 || exit 95; test -e $@ && exit 0; \
 	$(cmd_LD); \
-	) 95> $@.lock; exitcode=$$?; test $$exitcode = 95 || break; sleep 1; done; \
+	) 9> $@.lock; exitcode=$$?; test $$exitcode = 95 || break; sleep 1; done; \
 	rm -f $@.lock; exit $$exitcode