Re: Reconsider defaults for use-package-vc-prefer-newest

[Eli Zaretskii <eliz@gnu.org>]

> From: "Martin Edström" <meedstrom@runbox.eu>
> CC: "emacs-devel" <emacs-devel@gnu.org>
> Date: Sun, 15 Sep 2024 19:38:55 +0200 (CEST)
> 
> Now that we're on Emacs 30.0.91, I feel the need to call this out as a fairly release-critical bug. Perhaps I should have emailed bug-gnu-emacs, but now that'd split the discussion over two places, so I'll keep it here.
> 
> If this is the kind of setting we can flip in a patch release, then there's no rush. Maybe someone can weigh in about that.
> 
> Otherwise it would remain as a source of instability for many years, and conscientious devs would have to insert a check for Emacs 30 that reminds the user that the package may be terribly outdated.
> 
> At least one other developer agrees the current setting is "fragile" (https://github.com/melpa/melpa/pull/9133#issuecomment-2351653325).

I've read this thread, and I must confess that I'm not convinced.
Besides being waaay too late for such changes in Emacs 30, I also
don't think we have enough experience at this time to make such
decisions.  Both package-vc and use-package are relatively very new in
Emacs, and we have yet to collect enough user experience and
understanding of what are the expectations and how they should work
together.  Moreover, use-package-vc-prefer-newest is a new option in
Emacs 30, and we rarely make new optional behaviors take effect by
default as soon as they are introduced, to avoid behavior changes
which will surprise and perhaps annoy.  We made it an option to make
it easily adaptable to user preferences and needs.

Some of the rationale (like outdated Package-Version) also sounds like
it isn't our problem to solve.  It should be easy for the respective
package developers to get their act together in this matter.  It is
also TRT for them.  When a user uses use-package, he/she doesn't
necessarily want the latest commit, so the change isn't as obvious as
you make it sound, IMO.

Bottom line: I think no catastrophe happens if Emacs 30 is released
with the current default value of use-package-vc-prefer-newest.  It's
a user option, so customizing it is easy for people who want the
latest commit.  Even if we are making a mistake (for reasons we will
learn later), first time you do something there are always some rough
edges, so we can be excused for not realizing something due to lack of
experience.

Thanks.