We need to make sure Firefox/Devedition/Fennec don't step on each others toes. For this reason, we came up with a race-condition mini-condition in bug 1344229, more specifically[1]. But this is not all. We also need to make the tagging part idempotent so that we can rerun this script without the fear of retagging. Some groundwork has been done in bug 1346465. We could do this by taking that initial list of tags[2] and see if it's already generated in the list of tags. For that we need to double-check the returning code of the `self.hg_tag` method if any, and correlate it. [1]: https://hg.mozilla.org/releases/mozilla-beta/rev/c32166f8c0c4 [2]: https://hg.mozilla.org/releases/mozilla-beta/file/tip/testing/mozharness/scripts/release/postrelease_version_bump.py#l175

Comment on attachment 8937142 [details] bug 1425215 , bug 1417697 - version bump idempotency that supports relbranches. https://reviewboard.mozilla.org/r/207848/#review213768 LGTM!

Pushed by asasaki@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/9fd410272394 bug 1417697 - version bump idempotency that supports relbranches. r=rail