Example build:

https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8934287332633320208


Publishing the buildspec fails if manifest-versions is updated:


15:08:15: INFO: Updating version file to: 10775.24.0
15:08:15: INFO: Pushing to branch (_RemoteRef(remote=u'cros', ref=u'refs/heads/firmware-nami-10775.B', project_name=u'chromiumos/overlays/chromiumos-overlay')) with message: Incremented to version: 10775.24.0 
15:08:20: INFO: Creating buildspec: buildspecs/69/10775.24.0.xml
15:08:24: INFO: Creating buildspec: buildspecs/69/10775.24.0.xml as /b/swarming/w/ir/cache/cbuild/repository/manifest-versions-internal/buildspecs/69/10775.24.0.xml
15:09:03: ERROR: Traceback (most recent call last):
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/cbuildbot/stages/generic_stages.py", line 703, in Run
    self.PerformStage()
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/cbuildbot/stages/workspace_stages.py", line 198, in PerformStage
    dryrun=self._run.options.debug)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/cbuildbot/manifest_version.py", line 495, in GenerateAndPublishOfficialBuildSpec
    dryrun)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/cbuildbot/manifest_version.py", line 443, in PopulateAndPublishBuildSpec
    manifest_versions_int, rel_build_spec, manifest, dryrun)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/cbuildbot/manifest_version.py", line 417, in _CommitAndPush
    git.PushBranch(PUSH_BRANCH, manifest_repo, dryrun=dryrun)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/lib/git.py", line 1371, in PushBranch
    GitPush(git_repo, branch, remote_ref, skip=dryrun)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/lib/git.py", line 1272, in GitPush
    **kwargs)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/lib/git.py", line 785, in RunGit
    return cros_build_lib.RunCommand(['git'] + cmd, **kwargs)
  File "/b/swarming/w/ir/cache/cbuild/repository/chromite/lib/cros_build_lib.py", line 647, in RunCommand
    raise RunCommandError(msg, cmd_result)
RunCommandError: return code: 1; command: git push origin temp_auto_checkin_branch:refs/heads/master
To https://chrome-internal.googlesource.com/chromeos/manifest-versions
 ! [rejected]                temp_auto_checkin_branch -> master (fetch first)
error: failed to push some refs to 'https://chrome-internal.googlesource.com/chromeos/manifest-versions'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
cmd=['git', 'push', 'origin', 'temp_auto_checkin_branch:refs/heads/master'], cwd=/b/swarming/w/ir/cache/cbuild/repository/manifest-versions-internal

15:09:03: INFO: Translating result return code: 1; command: git push origin temp_auto_checkin_branch:refs/heads/master
To https://chrome-internal.googlesource.com/chromeos/manifest-versions
 ! [rejected]                temp_auto_checkin_branch -> master (fetch first)