Improve messaging for when a merge request is dropped from a merge train
When a merge request is dropped from a merge train a message explaining why is presented to the user on the merge request. However, this message is a bit vague. Additional details about the nature of the problem can help users troubleshoot.
Problem to solve
A customer reported (internal link only) that a merge request was dropped from a merge train and they weren't sure why. The merge request had the following comment added to explain why the merge request was dropped:
<USERNAME> removed this merge request from the merge train because 9:Failed to create merge commit for source_sha c8fc16dd and target_sha ad144da9 at refs/merge-requests/XXXX/train.
Proposal
I propose we add some more details about the failure to assist users with troubleshooting, so they can re-add the merge request to a merge train successfully.