alt Hacker NewsIt's unfortunate that change IDs aren't considered. There was a discussion [1] in 2025, and it has resurfaced a couple of times since.
Basically, the idea is to attribute a new kind of ID to an initial 'change'. During review, or whenever a commit is rebased, the change ID is kept, whereas the commit of course changes. This allows tooling to identify all previous versions of a change, and is what enables "per-commit" code review à la Gerrit [2] (which IMO is a much better experience than the branch-review-squash model that GitHub normalized). It's also used in jj, although I'm not familiar with that.
As of today, any tool that wants a change ID needs to somehow encode it in commit message bodies. The proposed discussion was about making a change ID a standard header field that git would natively keep across rebases.
[1] https://lore.kernel.org/git/[email protected]/T/#mf941...
[2] https://gerrit-review.googlesource.com/Documentation/user-ch...
Replies
Having switched to jj I totally agree. Change IDs are a huge UX win.
Yeah, "standardizing" change IDs would make it much easier to develop further tooling around it. In particular decentralized review is something that I'd be interested in.
For example, if GitHub is down, that would not be a blocker to access review comments or to do reviews. And maybe you could push your reviews to a GitLab mirror if you want a UI.
JJ and GitButler already create and inject this into the commit headers (using the same interoperable reverse-hex format), which is recognized by Gerrit and some forges like Tangled for incremental commit based review.
I doubt that core Git will adopt it anytime soon as it was not discussed at this years contributor summit (last week) and doesn't seem to be a hot topic on the ML.
What I would like to see is support for `git rebase` not dropping it, which is the current main issue. The `git replay` command, as well as commands based on the same sequencing code (`git history` for example) do not drop custom headers like this, so there is partial non-breakage, but several of the other history editing commands do drop custom headers.