So, this broke beta today, even though the attachements have not landed on Beta, here is what happened and why.
- L10n repos have a merge of l10n strings from all trees, and localizes work from this merged state when creating updates for any release (e.g. beta)
- This landing on central caused browser/locales/[en-US]/browser/aboutLogins.ftl to become available for localizers
- Some localizers translated aboutLogins.ftl, causing that file to be present in their repositories.
- On central-only this patch removed an explicit add to the .jar file from the in-gecko-repo copy of aboutLogins.ftl https://hg.mozilla.org/mozilla-central/rev/a7a32d0abbf9#l3.12 (this removal didn't happen on beta)
- On both beta and central we use globs to find any *.ftl file in the locale repository to include the ftl files for the build
- On locales with aboutLogins.ftl translated this caused us to have a manifest add for aboutLogins.ftl due to both the glob and the explicit add on beta.
And then beta broke because the code cannot cope with this state.
I fixed this over in Bug 1569807 by reverting the locale updates so we could confidently unblock todays beta, however we will need a better fix to land on beta/l10n-repos/something to address this in time for Thursdays Go-To-Build for beta.
Sending a n-i to flod and jaws to discuss and address. I'll be available to discuss as well incase there are any questions/concerns.