Re: Overlays

[ludo@gnu.org (Ludovic Courtès)]

Amirouche Boubekki <amirouche.boubekki@gmail.com> skribis:

> The issue I see is that some one wants to distribute recipes but
> doesn't want to contribute them in the guix repository. One way to do
> that is to fork the guix repository and merge once in a while and then
> ask the users to install packages using the command used during
> development from the forked repository. Otherwise, if overlays were
> supported users would just have to install overlays somewhat like apt
> sources and use the same command as with guix distribution recipes.

Without touching the Guix code, Guix users can always create their own
modules containing their own package recipes.  For instance, in
my-own.scm, one could write:

  (define-module (my-own)
    #:use-module (guix packages)
    ...)

  (define-public my-own-package
    (package
      (name "my-own")
      ...))

All the API is usable from there, in particular ‘package-derivation’.

From the command-line, one can run:

  guix build -e '(@ (my-own) my-own-package)'

or:

  guix package -e '(@ (my-own) my-own-package)'

What does not work, though, is:

  guix package -i my-own

So, to me, that’s what we’d want to fix.

>> In Guix, third parties could distribute their own Guile modules that
>> define packages. Guix would need a way to nicely deal with them at the
>> command line, but otherwise it’s just Guile modules.
>
> IIRC in nixos one just has to use the command «nix-env -i
> path/to/nix/package» to install a recipe out of nixpkg tree, I'm not
> sure it's supported by guix.

It is, see above.  :-)

> Anyway, the reason I raised now this feature is because:
>
> - I find it a useful feature, but the features you proposed for 0.4
> are way more interesting for the time being
> - One user complained on IRC that overlays could *streamline* recipes
> contributions that said contributing packages is not difficult using
> the guix repository
>
> So what I propose is to put this feature request in a TODO to avoid
> future loosly backed request like mine (except if someone wants to
> work on this) and focus on the 0.4 roadmap :)

Agreed!

Thanks for explaining,
Ludo’.