Backport fails without any output

[serhiy-storchaka]

I tried to trigger backporting python/cpython#114558 to 3.12 several times. Every time @miss-islington reports that it starts working, but do not produce any output.

Backporting to 3.11 failed due to conflicts, and this was reported.

It successfully creates backports to 3.12 for other PRs.

[Mariatta]

Here's the error message for that particular PR:

Jan 26 23:59:08 miss-islington app/worker.1 [2024-01-27 07:59:08,514: WARNING/ForkPoolWorker-1] {"message":"Validation Failed","errors":[{"resource":"PullRequest","code":"custom","message":"A pull request already exists for miss-islington:backport-07236f5-3.12."}],"documentation_url":"https://docs.github.com/rest/pulls/pulls#create-a-pull-request"}

[hugovk]

Here's the branch: https://github.com/miss-islington/cpython/tree/backport-07236f5-3.12

And the PR: python/cpython#114624

It looks like Miss Islington force-pushed the branch each time after commenting "I'm working now to backport this PR" on the upstream PR python/cpython#114558, but never commented that the backport was created.

[Mariatta]

Bedevere should have been the one to post that the backport PR has been created, but this only gets triggered once: the first time the PR is created.

Perhaps at that time bedevere errored out and didn't post the message.

[Mariatta]

So I think this is due to the merge commit message is not written correctly, and so bedevere did not link the backport PR with the correct original PR.

[webknjaz]

In my bot, I have more extensive reporting if somebody needs to borrow ideas: https://github.com/sanitizers/patchback-github-app/blob/5bd473a3e3593039610c8be502c011fbe0e21306/patchback/event_handlers.py#L388-L482