Re: core-updates: Emacs is only supported on x86_64-linux?

[Mark H Weaver <mhw@netris.org>]

Hi Chris,

Chris Marusich <cmmarusich@gmail.com> writes:
> I've confirmed that works for emacs, except that you actually have to
> also do it for gtk+, too, since rust gets pulled in via gtk+ also.

Ugh.  I'd prefer to avoid removing 'gtk+' from the inputs to 'emacs' on
any system, because the distinguishing characteristic of that package
(compared with the other Emacs variants) is that it's the Gtk+ variant
of Emacs.

For now, it would be good to eliminate the Gtk+ dependency on Rust.
If we reach the point where our Gtk+ package is only supported on
'x86_64-linux', our claim of supporting multiple architectures will
become increasingly dubious.

Does anyone know how Gtk+ depends on Rust?

Aside: I wish that Guix included a convenient tool to answer the
question "Why does package X depend on package Y?", i.e. "What paths of
dependencies lead from package X to package Y?", without having to view
the entire dependency graph (which is often too complex to grasp
visually).

For now: how about changing the failing system test to inherit from
'emacs-no-x-toolkit' instead of 'emacs'.  That, combined with making
'librsvg' a conditional input to Emacs (but leaving 'gtk+' in Emacs'
inputs on all systems), should be enough to get past your immediate
problem.

What do you think?

> From e36c4cab40c5b97ffedc72acc586c0b560e7868e Mon Sep 17 00:00:00 2001
> From: Chris Marusich <cmmarusich@gmail.com>
> Date: Sun, 7 Mar 2021 15:58:19 -0800
> Subject: [PATCH] gnu: rust: Make it "supported" on all systems but i686-linux.
>
> * gnu/packages/rust.scm (rust-1.30)[supported-systems]: Instead of hard-coding
> this to just "x86_64-linux", calculate the supported systems by deleting
> "i686-linux" from %supported-systems.

I don't think we should do this until we have reason to believe that our
Rust packages actually build successfully on the other systems.

> I think both of these patches are important and needed.  The patch to
> restore supported systems to the rust package is important because we
> will want rust to build successfully on many systems.

I agree that we must soon prioritize getting Rust working on other
systems, but I doubt that this simple patch will accomplish much more
than to waste precious cycles on our few non-Intel build slaves.

       Mark