[bug#46031] services: cuirass: Add "simple-cuirass-services".

[Ludovic Courtès]

Hi,

Mathieu Othacehe <othacehe@gnu.org> skribis:

>> I guess the first step would be to provide an a ‘package-channel(s)’
>> procedure that does like ‘package-provenance’, but returns a list of
>> channels.
>
> Seems fine to me. Here's an implementation attached. If it works for
> you, the next step will be to make the "cuirass-jobs" procedure of
> "gnu-system.scm" operate on channels I guess.

But by definition, “gnu-system.scm” is about the 'guix channel.
Intuitively I’d expect channel handling to happen in user code: either
in the user-provided manifest, or in some helper code in Cuirass.  WDYT?

> From d44dcd5d153ba0a4627c205f24a0741384f3d301 Mon Sep 17 00:00:00 2001
> From: Mathieu Othacehe <othacehe@gnu.org>
> Date: Tue, 23 Feb 2021 14:24:39 +0100
> Subject: [PATCH] describe: Add package-channels.
>
> * guix/describe.scm (package-channels): New procedure.

[...]

> +(define (package-channels package)
> +  "Return the list of channels providing PACKAGE or an empty list if it could
> +not be determined."
> +  (match (and=> (package-location package) location-file)
> +    (#f #f)

The #f return value doesn’t match the docstring.

> +    (file
> +     (let ((file (if (string-prefix? "/" file)
> +                     file
> +                     (search-path %load-path file))))
> +       (and file
> +            (string-prefix? (%store-prefix) file)
> +
> +            (filter-map
> +             (lambda (entry)
> +               (let ((item (manifest-entry-item entry)))
> +                 (and (or (string-prefix? item file)
> +                          (string=? "guix" (manifest-entry-name entry)))
> +                      (manifest-entry-channel entry))))
> +             (current-profile-entries)))))))

To avoid duplication, perhaps you should rewrite ‘package-provenance’ in
terms of ‘package-channels’?

Otherwise LGTM, thanks!

Thanks,
Ludo’.