Hi,

Out of any network, I get this error:

--8<---------------cut here---------------start------------->8---
$ guix time-machine --commit=1971d11d -- describe
guix time-machine: error: failed to load '/home/simon/.config//guix/channels.scm':
guix/build/download.scm:399:8: In procedure open-socket-for-uri:
In procedure getaddrinfo: Name or service not known
--8<---------------cut here---------------end--------------->8---

And that’s annoying.  It comes from:

        $ cat /home/simon/.config//guix/channels.scm
        (use-modules (guix ci))

        (list (channel-with-substitutes-available
               %default-guix-channel
               "https://ci.guix.gnu.org"))

as documented by section “Channels with Substitutes” [1].

Specifically, the error is raised by the procedure ’load*’ called by
’channel-list’ inside ’load-channels’.  Other said, ’load*’ runs the
procedure ’channel-with-substitutes-available’ which asks network via
the procedure ’find-latest-commit-with-substitutes’.

I think this is incorrect; the correct behaviour seems trying to do as
most as possible.  With the attached patch, I get:

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix time-machine --commit=1971d11d -- describe
guix time-machine: warning: could not find available substitutes at https://ci.guix.gnu.org
  guix 1971d11
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 1971d11db9ed9683d5036cd4c62deb564842e1f6
--8<---------------cut here---------------end--------------->8---

Obviously, the option ’-q’ allows to bypass the problem. :-)  However,
it’s annoying because the default file channels.scm can be complex and
it still should work without any tweak, IMHO.

Well, the proposed fix is here to catch the error; maybe it could be
finer than #t.

WDYT?

Cheers,
simon


1: https://guix.gnu.org/manual/devel/en/guix.html#Channels-with-Substitutes