In our project, GitHub - scummvm/scummvm: ScummVM main repository we deliberately chose to use linear history, thus we force the PRs to be rebased, not merged
However, for a couple of months, this functionality is often not working on GitHub, as it displays that “This branch cannot be rebased due to conflicts”. This happens even with freshly rebased branches on top of the tip of the master. We see that primarily in bigger PRs.
A good example of it is one of the recent PRs: https://github.com/scummvm/scummvm/pull/2982 I was looking at it from different angles, it was repeatedly rebased on top of the master, but GitHub still unable to rebase it automatically.
I would appreciate any insights into the problem. Or at least the leads on where to look. The PR is creating a new directory and then goes with 1000+ commits exclusively over the files in this new directory, thus, even theoretically there could not be conflicts.
And independently of that, I wish GitHub at least provided the git logs from the rebase or the conflicting commit/files.