pull Rules.mak from top_srcdir as pointed out by Robert P. J. Day on the mailing list
diff --git a/applets/Makefile b/applets/Makefile
index 1552799..0d892f5 100644
--- a/applets/Makefile
+++ b/applets/Makefile
@@ -12,7 +12,7 @@
 endif
 srcdir=$(top_srcdir)/applets
 APPLETS_DIR:=./
-include $(top_builddir)/Rules.mak
+include $(top_srcdir)/Rules.mak
 include $(top_builddir)/.config
 include $(srcdir)/Makefile.in
 all: $(libraries-y)