bug 758748: change SOURCE_REPO var check from error to warn.

toolkit/xre/Makefile.in

@@ -227,7 +227,10 @@ ifdef MOZ_SOURCE_STAMP
   SOURCE_REPO := $(strip $(SOURCE_REPO))
   SOURCE_REPO := $(patsubst ssh://%,http://%,$(SOURCE_REPO))
   SOURCE_REPO := $(patsubst %/,%,$(SOURCE_REPO))
-  $(call errorIfEmpty,SOURCE_REPO)
+
+  # command set should change based on revision control use.
+  # warn for now in case (git, bzr, ...) is in use.
+  $(call warnIfEmpty,SOURCE_REPO) 
 
   # extra sanity check for old versions of hg, no showconfig support
   ifeq (http,$(patsubst http%,http,$(SOURCE_REPO)))