x/build/cmd/gerritbot: fails to import some PRs, Gerrit server refuses push due to an account being not found

[dmitshur]

PR golang/website#186 is currently failing to be imported into Gerrit (despite having a passing CLA check), and recent changes made in PR #55119 are also failing to be imported (see discussion on it). The Gerrit server is refusing the push with errors like "Account 'nnn' not found":

2022/10/03 15:27:22 processPullRequest: importGerritChangeFromPR(golang/website#186, nil): could not create change: running [git -C /root/.cache/gerritbot/tmp/worktree_golang_website_186 push -o nokeycheck origin HEAD:refs/for/master%m=This+Gerrit+CL+corresponds+to+GitHub+PR+golang%2Fwebsite%23186.%0A%0AAuthor%3A+Zamicol+%3Czamicol%40gmail.com%3E]: output: remote: 
remote: Processing changes: refs: 1        
remote: Processing changes: refs: 1        
remote: Processing changes: refs: 1, done            
To https://go.googlesource.com/website
 ! [remote rejected]   HEAD -> refs/for/master%m=This+Gerrit+CL+corresponds+to+GitHub+PR+golang%2Fwebsite%23186.%0A%0AAuthor%3A+Zamicol+%3Czamicol%40gmail.com%3E (Account '56813' not found
56813 does not identify a registered user or group)
error: failed to push some refs to 'https://go.googlesource.com/website'
; err: exit status 1

2022/10/03 15:30:01 processPullRequest: importGerritChangeFromPR(golang/go#55119, [...]): could not create change: running [git -C /root/.cache/gerritbot/tmp/worktree_golang_go_55119 push -o nokeycheck origin HEAD:refs/for/master]: output: remote: 
remote: Processing changes: refs: 1        
remote: Processing changes: refs: 1, done            
To https://go.googlesource.com/go
 ! [remote rejected]       HEAD -> refs/for/master (Account '59165' not found
59165 does not identify a registered user or group)
error: failed to push some refs to 'https://go.googlesource.com/go'
; err: exit status 1

The last successfully imported commit in PR #55119 was on Sept 19, and PR golang/website#186 that's failing to import is from Sept 22. This might be related to a recent configuration change on our Gerrit server 2 weeks ago (b/247734171), although it seems to only be affecting those 2 PRs right now while many other recent PRs are imported fine.

CC @golang/release.

[dmitshur]

This error isn't happening as of yesterday 9:22 am (EDT), both PRs have been updated at around that time.

[dmitshur]

I just checked and it doesn't seem this is happening on any newer PRs either. For reference, neither I nor @cagedmantis changed gerritbot, so the fix must've happened on the side of the Gerrit server. Closing, we can reopen or file a new issue if this happens again.