Something went wrong during merge. Please try again.

Summary

I am unable to merge to master in https://gitlab.com/opencraft/client/LabXchange/labxchange-ops using the UI on GitLab.com.

This has persisted for over a month, consistently. Only on that repo, others work fine. I can merge locally and push to master.

Others are able to merge to that repo's master using the UI. Significantly (and the reason I am reporting this as a bug now), I was able to merge via the UI yesterday twice when I unchecked Squash commits. Today, with Squash commits checked (as usual for me), it is again failing to merge.

Merge failed: Something went wrong during merge. Please try again. 

Steps to reproduce

I have described the observed behaviour as clearly as possible above, but I cannot reproduce it in other repositories.

What is the current bug behavior?

Merge request fails to merge.

What is the expected correct behavior?

Merge request should merge.

Relevant logs and/or screenshots

As above.

Output of checks

This bug happens on GitLab.com

Possible fixes

I can see the error (StandardError) is handled in https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/services/merge_requests/ff_merge_service.rb#L21 but I don't have time to figure out where that error is being raised.

Can we replace the generic error message with a more explicit description of what actually failed?