bug#64487: 29.0.92; Another tree-sitter warning inside Custom

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 26 Feb 2024 18:25:33 +0200
> Cc: 64487@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 06/07/2023 12:12, Eli Zaretskii wrote:
> >> Date: Thu, 06 Jul 2023 14:56:44 +0800
> >> From:  Po Lu via "Bug reports for GNU Emacs,
> >>   the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> >>
> >> Type M-x customize RET.  Click Programming and then Languages.  A
> >> *Warnings* buffer will be displayed containing the following message:
> >>
> >>    Warning (treesit): Cannot activate tree-sitter, because language
> >>    grammar for ruby is unavailable (not-found): (libtree-sitter-ruby
> >>    libtree-sitter-ruby.0 libtree-sitter-ruby.0.0 libtree-sitter-ruby.so
> >>    libtree-sitter-ruby.so.0 libtree-sitter-ruby.so.0.0) No such file or
> >>    directory
> > 
> > When you customize a group, Custom loads all the packages that belong
> > to the group.  So in this case it loads ruby-ts-mode, and you get the
> > warning.
> 
> Which was never a problem before when simply loading a package didn't 
> alter auto-mode-alist.

You want to start that old dispute again?  I didn't expect you to
change your opinions, and you shouldn't expect me to change mine.  So
why restart that?

> Do I understand it right that performing the simple steps that Po Lu 
> outlined would silently assign ruby-ts-mode to *.rb files? And a bunch 
> of other such modes that get loaded as well. But only until the end of 
> the session.

Could be, I didn't try.  If that's what happens, patches to avoid such
a long-lasting effect, without changing what happens when the package
is loaded outside of the Customize context, will be welcome.