Re: Potential ABI breakage in upcoming minor releases

On Fri, Nov 15, 2024 at 03:29:21PM -0500, Tom Lane wrote:
> Noah Misch <noah(at)leadboat(dot)com> writes:
> > On Fri, Nov 15, 2024 at 10:09:54AM -0500, Tom Lane wrote:
> >> I'm starting to lean to the opinion that we need a re-wrap.
>
> > Perhaps. Even if we do rewrap for some reason, it's not a given that
> > restoring the old struct size is net beneficial. If we restore the old struct
> > size in v16.6, those who rebuild for v16.5 would need to rebuild again.
>
> I think what we should say is "sorry, 16.5 is broken for use with
> these extensions, use another minor version". If we don't undo the
> struct size change then 16.5 is effectively a major version update for
> affected extensions: they cannot build a binary release that works
> with both older and newer minor releases. That's a packaging
> disaster, especially if it impacts more than timescale. The more
> so if more than one release branch is affected.

Currently, we have Christoph Berg writing "I'd say the ship has sailed, a new
release would now break things the other way round." and you writing in favor
of undoing. It think it boils down to whether you want N people to recompile
twice or M>N people to recompile once, where we don't know N or M except that
M > N. Fortunately, the N are probably fairly well represented in this
thread. So to all: please speak up by 2024-11-16T17:00+0000 if you think it's
the wrong choice to bring back the v16.4 ABI and tell people to rebuild
extensions built against v16.5 (likewise for corresponding versions of
v14-v17). Currently, the plan of record is to do that.