bug#22629: Channels!

[Ludovic Courtès]

address@hidden (Ludovic Courtès) skribis:

> The patches that follow implement this last bit, though in a slightly
> different way.  Users would now have the option to provide
> ~/.config/guix/channels.scm along these lines:
>
>   (cons (channel
>          (name 'guix-hpc)
>          (url "https://gitlab.inria.fr/guix-hpc/guix-hpc.git";)
>          (branch "origin/master"))
>         %default-channels)

What follows is version 2 of the patches, which I’d like to push within
a day or two.  The main changes are:

  1. Added documentation for channels and ~/.config/guix/channels.scm.
     In particular I added a warning about compatibility that summarizes
     what we discussed.  Please let me know what you think.

  2. Added -C/--channels option to ‘guix pull’ to specify a channel
     file.

  3. Fixed ‘update-NEWS.scm’, which assumed that the last item of
     (%package-module-path) is Guix’s own set of modules.  We also find
     this pattern in guix-artwork.git/website and probably in other
     places, so we’ll have to adjust them.

Ludo’.