Looks like mozharness doesn't use tags from configs/multi_locale/release_mozilla-*.json files since it skips source updates while running mozharness multi l10n step. Is it safe to get rid of those tags and avoid changes like this http://hg.mozilla.org/build/mozharness/rev/4150091890a9 ?

We can get rid of those tags; they're no-op since we skip cloning those repos in mozharness currently. I have bug 608854 on file to get that script capable of doing a full multilocale build from start to finish; once that's done we can build Android and Maemo (and potentially all MercurialBuildFactory builds) fully in mozharness without any buildbotcustom work, other than a mozharness-friendly factory. We would want to re-add those tags, or some way to send the release config repo information down to the script, once that's done. This seems to be lower priority than mozmill and talosrunner, however, so it may be a while before it gets fixed.

Fixed in bug 679153.