--- old/make/SourceRevision.gmk	2017-10-05 11:55:56.632833882 +0200
+++ new/make/SourceRevision.gmk	2017-10-05 11:55:56.384837797 +0200
@@ -28,7 +28,7 @@
 include $(SPEC)
 include MakeBase.gmk
 
-$(eval $(call IncludeCustomExtension, , SourceRevision.gmk))
+$(eval $(call IncludeCustomExtension, SourceRevision.gmk))
 
 ################################################################################
 # Keep track of what source revision is used to create the build, by creating