--- a/make-rules/justmake.mk	Wed Feb 25 16:10:06 2015 -0800
+++ b/make-rules/justmake.mk	Thu Feb 26 06:52:41 2015 -0800
@@ -69,6 +69,8 @@
 
 # test the built source
 $(BUILD_DIR)/%/.tested-and-compared:    $(BUILD_DIR)/%/.built
+	$(RM) -rf $(COMPONENT_TEST_BUILD_DIR)
+	$(MKDIR) $(COMPONENT_TEST_BUILD_DIR)
 	$(COMPONENT_PRE_TEST_ACTION)
 	-(cd $(COMPONENT_TEST_DIR) ; \
 		$(COMPONENT_TEST_ENV_CMD) $(COMPONENT_TEST_ENV) \