alt Hacker NewsSuch as?
When you merge a commit in that changed a file that has been already changed since the common ancestor, Git runs a tool of your choice on this file. If the tool fails, it marks the file as needing a merge and doesn't let you commit it until you unmark it to confirm that you have merged it manually. In case of octopus merges, it will just abort early. That's basically its whole behavior when it comes to conflicts.
Such as moving down a fixup during interactive rebase when it's going to conflict with parents, or I've added more commits mid-rebase, or the rebase started in a tool and now I need to think about the tool's command and understand how many times the rebase point is view is backwards to interpret which is "ours" and which is "theirs" and whether it's the tool, my editor, or my own experience I should ignore because it's going to mislead me.
None of that word salad should matter, but it does. Git will ruin everything with glee and there is always an excuse for why that's fine and it's the user's fault.