Yes, that’s roughly what I was expecting to be able to do by forking one GitLab repo to another, and I could then update the copy with ongoing changes from the original.
Rather like if I clone a repo from the command line, I can then “pull” and (if I have permissions) “push” to the origin, which is automatically set to be the repo I cloned.
I agree that if incompatible edits are made the two places then it will break (well, have merge conflicts that need solving), but that’s life, right? Removing the “pull” command would not be a solution
Looks to me like the mirror function is designed to mirror a non-GitLab repo into GitLab, presumably so you can use GitLab features on it but are not expecting to do any edits, you just want a running copy? (the UI for doing mirroring seems to take no notice of the fact you’re on a forked repo).