[bug#38769] [PATCH] import: Add importer for MELPA packages.

[Brett Gilio <brettg@gnu.org>]

Carlo Zancanaro <carlo@zancanaro.id.au> writes:

> Hey Guix!
>
> I have for a while wanted to write an importer for MELPA packages that
> reads from the MELPA recipe and constructs a Guix package. This is
> primarily because the ELPA importer uses source tarballs, which we
> can't rely on for MELPA because they remove old tarballs and upload
> new ones whenever they rebuild the package.
>
> So, here is my importer!
>
> Probably the most controversial decision here is to always import the
> current head that MELPA would build. This means that when you run
> "guix import melpa" it gives you a package definition that should
> correspond to what MELPA currently has. This may not correspond to a
> release of the package, so we cannot easily give it a version, and
> thus I put the current date into the version string.
>
> I imagine it would be possible to combine this importer with the
> current ELPA one in some way, to use all the metadata provided by the
> ELPA importer, but then generate an origin based on the MELPA recipe,
> but that seemed more daunting to me than writing a new importer.
>
> Carlo
>
>

Hi Carlo! Thanks for your contribution. I have not yet had a chance to
look at it, but I agree that we /should/ combine this with the ELPA
importer in its current tradition: `guix import elpa -a melpa`. That
seems preferable to me, as it would avoid the need to deprecate a
command flag in our UX.

What do you think?

-- 
Brett M. Gilio
GNU Guix, Contributor | GNU Project, Webmaster
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<brettg@gnu.org> <brettg@posteo.net>