bug#65740: No fallback to SWH for .guix-channel dependencies

bug#65740: No fallback to SWH for .guix-channel dependencies

[Simon Tournier]

Hi,

Consider this channels.scm file:

--8<---------------cut here---------------start------------->8---
$ cat /tmp/channels.scm
(list (channel
        (name 'guix)
        (url "https://git.savannah.gnu.org/git/guix.git")
        (branch "master")
        (commit
          "710d9050524213a83e4ce9efe9765d7fbc233839"))
      (channel
        (name 'bimsb)
        (url "https://github.com/BIMSBbioinfo/guix-bimsb.git")
        (branch "master")
        (commit
          "240a599f77dab7dcb8d2ed091b90056e58a46c51")))
--8<---------------cut here---------------end--------------->8---

Then, assume Github is down forever.  Guix will lookup to Software
Heritage (SWH) for the channel bimsb.  So far, so good.  However, then
it fails:

--8<---------------cut here---------------start------------->8---
$ guix time-machine -C /tmp/channels.scm -- describe
Updating channel 'guix' from Git repository at 'https://git.savannah.gnu.org/git/guix.git'...
Updating channel 'bimsb' from Git repository at 'https://github.com/BIMSBbioinfo/guix-bimsb.git'...
/tmp/channels.scm:95:6: warning: channel 'bimsb' lacks 'introduction' field but '.guix-authorizations' found
Updating channel 'guix-past' from Git repository at 'https://gitlab.inria.fr/guix-hpc/guix-past'...
guix time-machine: error: Git error: failed to resolve address for gitlab.inria.fr: Name or service not known
--8<---------------cut here---------------end--------------->8---

The main reason is because the channel bimsb contains the file
.guix-channel which reads,

--8<---------------cut here---------------start------------->8---
(channel
 (version 0)
 (dependencies
  (channel
   (name guix-past)
   (url "https://gitlab.inria.fr/guix-hpc/guix-past"))
  (channel
   (name guix-science)
   (url "https://github.com/guix-science/guix-science.git"))))
--8<---------------cut here---------------end--------------->8---

And Guix is not able to fallback to SWH for these channels.

Corollary, even if it was able, what is the correct revision of
the guix-past or guix-science channels?

This report is about two bugs:

 1. transparent fallback to SWH for .guix-channel dependencies

 2. pin all channels when running “guix describe”, even the ones from
   .guix-channel dependencies.

This #2 is annoying because it makes the workflow:

    guix time-machine -C channels.scm -- shell -m manifest.scm

unpractical when user relies on channels with dependencies.

Cheers,
simon

bug#65740: No fallback to SWH for .guix-channel dependencies

[Ludovic Courtès]

Hi,

Simon Tournier <zimon.toutoune@gmail.com> skribis:

> The main reason is because the channel bimsb contains the file
> .guix-channel which reads,
>
> (channel
>  (version 0)
>  (dependencies
>   (channel
>    (name guix-past)
>    (url "https://gitlab.inria.fr/guix-hpc/guix-past"))
>   (channel
>    (name guix-science)
>    (url "https://github.com/guix-science/guix-science.git"))))
>
> And Guix is not able to fallback to SWH for these channels.

Yes, but that’s expected: we’re not specifying any commit, only the URL,
so there cannot be any sort of fallback.

> Corollary, even if it was able, what is the correct revision of
> the guix-past or guix-science channels?
>
> This report is about two bugs:
>
>  1. transparent fallback to SWH for .guix-channel dependencies
>
>  2. pin all channels when running “guix describe”, even the ones from
>    .guix-channel dependencies.

#1 happens, but only when channels are pinned (returned by ‘guix
#describe’).

Re #2, I don’t think there’s such a bug, is there?  In the example
below, ‘guix describe’ shows 4 channels (including dependencies), not 2:

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix time-machine -C <(echo '(cons (channel (name (quote bimsb)) (url "https://github.com/BIMSBbioinfo/guix-bimsb.git")) %default-channels)') -- describe -f channels

[...]

(list (channel
        (name 'guix)
        (url "https://git.savannah.gnu.org/git/guix.git")
        (branch "master")
        (commit
          "4dd33fc62899134606f36f92594cf160b972f685")
        (introduction
          (make-channel-introduction
            "9edb3f66fd807b096b48283debdcddccfea34bad"
            (openpgp-fingerprint
              "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"))))
      (channel
        (name 'bimsb)
        (url "https://github.com/BIMSBbioinfo/guix-bimsb.git")
        (branch "master")
        (commit
          "240a599f77dab7dcb8d2ed091b90056e58a46c51"))
      (channel
        (name 'guix-science)
        (url "https://github.com/guix-science/guix-science.git")
        (branch "master")
        (commit
          "1ad5192cff0d7b34a2f74592c6896f901d1c9ccd"))
      (channel
        (name 'guix-past)
        (url "https://gitlab.inria.fr/guix-hpc/guix-past")
        (branch "master")
        (commit
          "1e25b23faa6b1716deaf7e1782becb5da6855942")))
--8<---------------cut here---------------end--------------->8---

Thanks,
Ludo’.

bug#65740: No fallback to SWH for .guix-channel dependencies

[Simon Tournier]

Hi,

On Fri, 08 Sep 2023 at 22:40, Ludovic Courtès <ludo@gnu.org> wrote:

>> This report is about two bugs:
>>
>>  1. transparent fallback to SWH for .guix-channel dependencies
>>
>>  2. pin all channels when running “guix describe”, even the ones from
>>    .guix-channel dependencies.
>
> #1 happens, but only when channels are pinned (returned by ‘guix
> #describe’).
>
> Re #2, I don’t think there’s such a bug, is there?  In the example
> below, ‘guix describe’ shows 4 channels (including dependencies), not 2:

My bad!

I had probably not done what I always recommend: “guix describe“.

Sorry for the noise.

Cheers,
simon