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Comment by dpatterbee | Hacker News Reader

Git rebases don't work if there are conflicts, jj doesn't have this problem. Also idk if you can rebase onto multiple parents with git but jj can do it.

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Can you explain how conflicts are not conflicts?

If I change a line of code several times and rebase on to a branch that changed the same lines of code, how are you sure what the right one is?

JJ can save conflict related state with the change so that you don't need to resolve a conflict in the middle of a stack of changes for rebasing to continue for the remaining changes. Concretely, it uses a "conflict algebra" where it can track the impact of a conflict as it propagates through the stack of rebased changes: https://docs.jj-vcs.dev/latest/technical/conflicts/

That sounds like https://git-scm.com/book/en/v2/Git-Tools-Rerere ?

Not really very similar at all for the scenario discussed here. Rerere remembers how you have resolved a conflict before. It doesn't let you rebase a stack of commits that result in different conflicts. You will have to stop and resolve each conflict and then `git rebase --continue`.

However, the conflict algebra does remove many common uses of rerere. See https://github.com/jj-vcs/jj/issues/175#issuecomment-1079831... for a longer discussion.

Avoiding manual conflict resolution isn't really a good thing though - conflicts are an indication that multiple different changes affect some code and you really should think hard about what the combination of them should be. Even what git does automatically already can be dangerous.

I agree, but that doesn't seem relevant. I did not say the jj automatically resolves conflicts.

But what does that bring? Your code won't compile as long as you don't fix the conflicts, so anyway you have to fix them when you rebase, right?

You have to fix them at some point, but not in the middle of doing other things. Right now. With no possible way to make progress elsewhere while deferring this decision.

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