Bug 1873959 - Only force generation of buildid.h and source-repo.h during export phase r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D198180

Makefile.in

@@ -24,7 +24,13 @@ endif
 include $(topsrcdir)/config/config.mk
 
 ifneq (mobile/android,$(MOZ_BUILD_APP))
-$(MDDEPDIR)/buildid.h.stub $(MDDEPDIR)/source-repo.h.stub: FORCE
+# We only want to generate buildid.h once, during the export phase.
+ifeq ($(MAKECMDGOALS),buildid.h)
+$(MDDEPDIR)/buildid.h.stub: FORCE
+endif
+ifeq ($(MAKECMDGOALS),source-repo.h)
+$(MDDEPDIR)/source-repo.h.stub: FORCE
+endif
 endif
 source-repo.h: $(MDDEPDIR)/source-repo.h.stub
 buildid.h: $(MDDEPDIR)/buildid.h.stub