superproject: change the warning message to say it is beta.

$ repo_dev init --use-superproject -u
remote: Total 3 (delta 0), reused 3 (delta 0)
NOTICE: --use-superproject is in beta; report any issues to the address described in `repo version`

$ ./run_tests -v

Bug: [google internal] b/189946009
Change-Id: Ifb3ef266a72b67f3c4a2a3ac2033b10e03b789d4
Reviewed-by: Jonathan Nieder <>
Tested-by: Raman Tenneti <>
diff --git a/ b/
index 62f2d52..f7ccd57 100644
--- a/
+++ b/
@@ -173,8 +173,8 @@
       True if sync of superproject is successful, or False.
-    print('WARNING: --use-superproject is experimental and not '
-          'for general use', file=sys.stderr)
+    print('NOTICE: --use-superproject is in beta; report any issues to the '
+          'address described in `repo version`', file=sys.stderr)
     if not self._manifest.superproject:
       print('error: superproject tag is not defined in manifest',