possible race condition: target branch change after PR creation isn't being accounted for

[lsm5]

What happened? What is the problem?

See: containers/skopeo#2285 . The PR was initially created with the target branch as main which was later changed to release-1.13. The copr build jobs failed as packit was trying to merge the PR into the upstream main branch as set at the time of PR creation.

I guess the workaround would be to just submit a new PR with the correct branch from the get-go.

What did you expect to happen?

• Packit should use the latest / current branch for jobs and not the branch at PR creation time.
• Even better if copr builds and other jobs can be auto-retriggered on branch change.

Example URL(s)

See PR in description.

Steps to reproduce

1. create PR
2. change branch
3. retrigger copr jobs (maybe)

What is the impacted category (job)?

Copr builds

Workaround

• There is an existing workaround that can be used until this issue is fixed.

Participation

• I am willing to submit a pull request for this issue. (Packit team is happy to help!)

[lsm5]

This seems to be a rare race. Also, containers/skopeo#2296 earlier mentioned in description is not actually an example of this bug as initially suspected, so I removed it from description.

In the PR referenced in description, the branch was changed right away after PR creation containers/skopeo#2285 (comment) and I'm unable to reproduce that on containers/skopeo#2299 . But maybe that helps to tighten constraints further.