[bug#53388] New package: gallery-dl

[Leo Famulari <leo@famulari.name>]

On Thu, Jan 20, 2022 at 11:48:25AM +0000, Bird wrote:
> The attached patch adds a new package: gallery-dl in
> gnu/packages/video.scm

> From 799d589e6b5d76b4cac6272d22f87603729fb9e1 Mon Sep 17 00:00:00 2001
> From: Bird <birdsite@airmail.cc>
> Date: Thu, 20 Jan 2022 11:42:24 +0000
> Subject: [PATCH] gnu: gallery-dl: Add a new package. *
>  gnu/packages/video.scm(gallery-dl): Add package.

Hello, and thanks for the patch!

I applied it to a Git checkout of the Guix source code, and tried
rebuilding Guix, as described here in the Contributing chapter of the
manual:

https://guix.gnu.org/manual/devel/en/html_node/Building-from-Git.html

However, it crashes like this:

------
ice-9/eval.scm:293:34: error: gpl2+: unbound variable
hint: Did you forget `(use-modules (guix licenses))'?

make[2]: *** [Makefile:7380: make-packages-go] Error 1
make[2]: Leaving directory '/home/leo/work/guix'
make[1]: *** [Makefile:6453: all-recursive] Error 1
make[1]: Leaving directory '/home/leo/work/guix'
make: *** [Makefile:3982: all] Error 2
------

The reason for this error is that licenses in the gnu/packages/video.scm
module are "prefixed" to avoid a namespace collision between packages
and licenses with the same name, such as zlib and expat:

https://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/video.scm?id=f223535e1c2f052f671e44a6c546d0ebde3591b1#n80

You can check other packages in that module for examples of how to
prefix the license.

> +    (license gpl2+)

I checked several of the .py files in the source code, and setup.py, and
they all seem to specify that the program is made available under the
terms of version 2 of the GPL, but no later versions. So, this package
should use "gpl2", not "gpl2+".

> +    (arguments
> +     '(#:tests? #f))))

We always run upstream test suites in Guix packages, because it helps
validate our packaging and finds bugs to assist upstream development.
If we do not run the tests, we add a code comment explaining why. In
Scheme, comments begin with the ; (semicolon) character.

So, can you send a revised patch that adjusts the license and either
runs the test suite or explains why not?

Thanks in advance!