[mathstuf]

That is what comments and commit messages are for. I trawl history all the time. Running into an unbisectable mess of a branch (because a bug that was introduced in commit X~15 is fixed in X on the same branch) is a complete nightmare. I have to discect the branch history and understand what is because of the branch and what is debugging/review/CI cycle cleanups. Commit messages for fixups also tend to be 100% terrible and utter trash. "Fix review comments". Thanks. If we're doing that, let's copy what the comment was in too and why it fixes it.

The problem with your request is that 90+% of the time (with the way I develop), the dead ends are on MRs that got closed or code that never got pushed in the first place. So again, comments as to why this approach is used is way better than hiding it in the history because someone coming to "clean up" code sees the thought process instead of having to remember to search for it.

[gmfawcett]

I don't do much work like that -- I suspect you're part of a much larger developer team -- but I think I understand the problem you're describing.

Couldn't you simply review/bisect at the fork/join points? i.e., take the commits at which forks began or ended, ignore any intermediary commits, and run the bisect (or, read diffs) across that subset? That way you're only comparing at the chapter-markers of the story, so to speak, and not getting mired in the gory details.

[mathstuf]

Yes, `git bisect --first-parent` was a feature I wanted for a long time. It finally exists now, so yes that helps, but is not a complete solution.

Even with `bisect --first-parent`, I still want useful commit messages which "fixup" commits, again, are uniquely terrible at being on the whole.

I do software process and other things, so some of my branches tend to be gigantic (e.g., revamping the build system) and can be 200+ commits because one cannot meaningfully land a build system rewrite incrementally. That one in particular was meant to be bisectable because when rebasing on top of new development, I wanted fixes to be in the "port this library over" commit instead of after some random merge commit based on when I decided to sync up that week (it took a year to do it). So once I get it down to a particular MR, being able to inspect that topic is still a useful property.

Note that this only works with a `merge --no-ff` workflow too. The `rebase && merge --ff-only` pattern and `merge --squashed` are both terrible, IME, at making useful history. The force-rebase workflow is just as confounding to me as the no-rebase workflow (the former de-parallelizes your MR merge process and the latter tends to make a terrible commit history).

Note that even for single-developer projects I run, I tend to make PRs even for my own changes (once it's gotten off the ground).