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

["Martin Edström" <meedstrom@runbox.eu>]

Sorry the last email was incomplete, my keyboard has a bug.

On Mon, 16 Sep 2024 14:34:55 +0300, Eli Zaretskii <eliz@gnu.org> wrote:

> > While the option is a new thing in Emacs 30, use-package :vc itself is a new thing in Emacs 30, so it is not as if there is an old behavior to emulate.  I should also point out that the module it was inspired by, vc-use-package, actually had the opposite default!  So, that setting has already been tested by lots of users on Emacs <29, and it is Emacs 30 that will change things.
> 
> Yes, you said that in your original message, and I understand that
> argument.  But as I responded, I'm not convinced the two options must
> always be in sync, as they are used differently for different purposes.

Okay, I'll accept that for the command package-vc-install, as I have not thought much about its use cases.  

I want to call attention to the old use-package :vc, shipped under the confusing name vc-use-package [1], that people could install on Emacs 29 and earlier.  The Emacs 30 use-package :vc is a drop-in almost 1:1 replacement for this thing.  It had the opposite default behavior from the default Emacs 30 is about to have.  That change needs justification, not the other way around!

[1] https://github.com/slotThe/vc-use-package

> > I should also point out that the catastrophe occurs not at release time, but years afterwards, when we're on Emacs 31, 32, 33... but devs still want to support Emacs 30, getting worse with time. So I do hope that it will be possible to change a setting like this with Emacs 30.2 or some other "bugfix" release.
> 
> There's no reason to do this for user options, since customizing an
> option if the user doesn't like its default is easy.

You cannot rely on users to configure this kind of thing for themselves, most of them would not know the reason why things broke. It is not a matter of "liking" the default, since breakage in one direction would be much more severe than is possible to encounter in the other direction (years out of date vs. slightly too new).

It is absolutely Emacs' responsibility, at least as long as stability for users is desired. Isn't it the reason to favor conservative defaults? Avoiding breakage? I get this new default comes from a good place, intending stability, but it is a radical departure from what has been the norm established by Straight/Quelpa/el-get and their use-package integrations, and that will work against stability.  

> 
> > As for making devs get their act together, sure, they could do that. But three problems with that attitude:
> > 
> > 1. It makes sense to impose requirements on devs who are submitting packages to NonGNU Elpa, but this setting affects everyone, including those who have not opted in to such requirements.
> > 2. Not every dev will get the memo, naturally, and the ones who get hurt in the meantime are users, who believe that the dev's package is broken when it is not (and the dev should not be punished for being out of the loop).
> > 3. The devs who do get the memo, and were previously content with a frozen Package-Version, will resent GNU for forcing what they perceive as a workaround. I do not think that is worth it.  Like it or not, MELPA has allowed many of us to taste of the convenience of git/hg tags, and it didn't use to be a problem... until Emacs 30. Now they have to adopt some toolchain like sisyphus.el and pollute the commit log with two extra commits for every new version, to solve what used to be a non-issue.
> 
> I consider advancing Package-Version when significant changes are made
> a simple and uncontroversial thing to do for any package developer.  I
> cannot imagine why someone who wants their package in good shape to
> regard this as some annoyance.

This email discussion risks getting long, but let me know if you want me to describe why I do not find it simple.  For now, I believe the relevant thing from Emacs' perspective is that there does exist developers who will not advance Package-Version, nevermind why.