On Fri, Oct 17, 2025 at 01:15:20PM -0400, Tom Lane wrote:
> FWIW, I favor the approach of having an in-tree, per-branch file
> containing the commit hash of a commit that is the current ABI
> reference for that branch. If the file doesn't exist (which it
> wouldn't in master, and probably not in recently-forked branches),
> skip ABI checking. I think this is superior to the discussed
> alternative of depending on git tags, because files are easy to
> change or remove, while tags are not. In particular, I think it'd
> likely be impossible to make the ABI reference point go backwards
> if we use tags. Maybe that's not a case we'd ever need, but I'm
> unconvinced of that.
I'm new to the topic, but IMHO the per-branch file approach is by far the
best approach. Not only is it much more flexible, but we could even use it
as a centralized list of ABI breaks for a given branch with justification
for each. I can't think of any strong advantages of keeping this stuff in
git metadata. git itself uses a file for blame.ignoreRevsFile...
--
nathan
