diff -r 000000000000 -r 6474c204b198 build/pymake/tests/include-dynamic.mk
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/pymake/tests/include-dynamic.mk	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+$(shell \
+if ! test -f include-dynamic.inc; then \
+  echo "TESTVAR = oldval" > include-dynamic.inc; \
+  sleep 2; \
+  echo "TESTVAR = newval" > include-dynamic.inc.in; \
+fi \
+)
+
+# before running the 'all' rule, we should be rebuilding include-dynamic.inc,
+# because there is a rule to do so
+
+all:
+	test $(TESTVAR) = newval
+	test "$(MAKE_RESTARTS)" = 1
+	@echo TEST-PASS
+
+include-dynamic.inc: include-dynamic.inc.in
+	test "$(MAKE_RESTARTS)" = ""
+	cp $< $@
+
+include include-dynamic.inc