diff -r 000000000000 -r 6474c204b198 build/pymake/tests/unexport.mk
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/pymake/tests/unexport.mk	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+#T environment: {'ENVVAR': 'envval'}
+
+VAR1 = val1
+VAR2 = val2
+VAR3 = val3
+
+unexport VAR3
+export VAR1 VAR2 VAR3
+unexport VAR2 ENVVAR
+unexport
+
+all:
+	test "$(ENVVAR)" = "envval" # unexport.mk
+	$(MAKE) -f $(TESTPATH)/unexport.submk
+	@echo TEST-PASS