CommitQueueSync failed on master-paladin:

https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8927481447489331008

https://luci-logdog.appspot.com/logs/chromeos/buildbucket/cr-buildbucket.appspot.com/8927481447489331008/+/steps/CommitQueueSync/0/stdout

16:32:19: INFO: Incremented version number to  11383.0.0-rc2
16:32:19: INFO: Publishing build spec for: 11383.0.0-rc2
16:32:19: INFO: Publishing with commit message: Automatic: Start master-paladin master 11383.0.0-rc2
CrOS-Build-Id: 3213841
16:32:28: INFO: Pushing to branch (_RemoteRef(remote='origin', ref='refs/heads/master', project_name=None)) with message: Automatic: Start master-paladin master 11383.0.0-rc2
CrOS-Build-Id: 3213841 
16:32:28: ERROR: Failed to generate LKGM Candidate. error: 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.

Some searching found that LKGM == Last Known Good Manifest, which should be the manifest of git repositories.

That step of attempting and failing to generate an LKGTM Candidate repeated many times until eventually some part of the system rightly decided to give up.

TBD if this is a one-off flake or if this will repeat.