One of the most annoying quirks of LLMs for me is the insistence on, after being corrected, loudly noting what wasn't done. After getting it to change something stupid in code, it will leave a comment in the code boasting about how it doesn't do the stupid thing, which to future readers reads like an 'asbestos free!' label on a cereal box.

Ha ha fair. But yeah shelling out to git and reusing the original tree object was deliberate means file contents can't change even if I screw up elsewhere.

why can't anyone just do things themselves anymore? it's all LLM crap

Why would you think such a project would reimplement git?

I've needed to do this for a bunch of reasons.

1. Sometimes I do a scraping project where I want the commit dates to match when the data actually changed, reconstructed from sources like the Internet Archive or the dates on https://platform.claude.com/docs/en/release-notes/system-pro... - for example here: https://github.com/simonw/research/commits/main/extract-syst... - or this project that attempted to reconstruct the history of Tim Berners-Lee's original browser: https://github.com/simonw/1991-WWW-NeXT-Implementation/commi...

2. Sometimes I split a Git repo into two, and I want to preserve the commit history (authors and dates) on the files that end up in the new repo - effectively replay the history of just one folder from the original to help create the new one.

3. I occasionally mess up cleaning up and merging a PR from an open source contributor such that the work is incorrectly credited to me. I'll fix the commit so that it credits the right person.

Yes, for instance it could be useful if someone’s been accidentally committing with a bogus email address. Or if you’re cleaning up some sort of mess and would like to recreate an accurate history.

Obviously as with any “force push” situation, the usual caveats apply if this is on a branch others have checked out, but if the mess is big enough, it is sometimes worth it to send everyone a script to reset or just to have people delete and re-check-out.

The few times I've wanted to completely rearrange a repo, It's been enough just make a backup branch and then dump the log from there and pull what I want.

I have script somewhere I think it's called git-cherry-replace, which soft resets a commit id and copies the commit message and optionally populates GIT_COMMITTER_DATE and whatnot.

What I described is probably simple enough that an LLM can implement it.

But unless you're trying to retroactively reconstruct something to preserve the exact meaning, you should consider whether a rebase even makes sense.

Yes. Absolutely! Many times I had a wrong configured terminal and messed up the author. Often I work in different projects, privately and in my work, and I use different authors for both

yes; when i wanted to make it look like i didn’t procrastinate for a week and implement the entire feature in one day

Times I have needed to do this:

  - An agent messed with my git config for some reason so I had to go back and fix the commit authorship
  - I created a PR mostly based on work that someone else did, so I reauthored most of the commits to be in their name

So, exactly like a knife? Generally we don't want to cut people open, but when we need to do it, like during surgery, a sharp knife sure helps.

Agreed mostly. The intent is local cleanup before you push like fixing a wrong author email across a batch or dates from a machine with a bad clock

No idea not an emacs person does magit handle bulk author/date edits or just reword? genuinely curious

https://imgur.com/a/V5EGCOw

Appreciate it! pick a commit, stab it

its vibecoded. just point another vibe based harness at it and youll have it in an hour or two. this thing is as trivial as you can get get, scope wise