+ifneq ($(SCAN_EXTRA),)
+SCAN_STAMP=tmp/info/.scan-$(SCAN_TARGET)-$(shell ls $(SCAN_EXTRA) 2>/dev/null | (md5sum || md5) 2>/dev/null | cut -d' ' -f1)
+$(SCAN_STAMP):
+ rm -f tmp/info/.scan-$(SCAN_TARGET)-*
+ mkdir -p $(shell dirname $@)
+ touch $@
+endif
+