Re: [PATCH] gnu: Add p7zip.

[Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>]

kei@openmailbox.org writes:

> On 2016-08-09 04:05, Ricardo Wurmus wrote:
>> Leo Famulari <leo@famulari.name> writes:
>> 
>>>> > I see that you took care of removing non-free parts in a patch and a
>>>> > build phase.  Since “guix build -S p7zip” doesn’t run the build phase
>>>> > users would still end up with a source archive containing the non-free
>>>> > parts.  The best way is thus to remove things in a snippet.
>>>> >
>>>> > In “shogun” from the “machine-learning” module we remove supporting code
>>>> > for non-free features in a snippet by cutting out anything between some
>>>> > ifdef markers, but looking at the patch I see that it wouldn’t be
>>>> > feasible for p7zip.
>>>> 
>>>> Also note that it is not completely desirable for nonfree code to be 
>>>> removed
>>>> with a patch, and is one of the reasons Guix supports snippets in the 
>>>> first
>>>> place.
>>> 
>>> Is there a reason to not use a patch in this case? Or can we proceed
>>> with packaging p7zip, using a patch to remove non-free parts?
>> 
>> We don’t want to have a “reverse image” of the non-free code in a 
>> patch.
>> Arguably that would just be a derivative of the non-free code, so we
>> also couldn’t freely distribute it.
>> 
> If this is the case, then should we alert the Parabola GNU/Linux-libre 
> packagers?
> The patch I submitted is the same one they use when installing p7zip 
> from the
> source code (see 
> https://git.parabola.nu/abslibre.git/tree/libre/p7zip/libre.patch).

I see.  I think we first need to figure out exactly what license applies
to which part of the code.  A big chunk of the patch is to remove
references to RAR stuff in the build system and the documentation; that
could probably be removed with a patch.  What is critical is code that’s
actually under the unRAR license.

A quick look at the patch shows me this:

> -  Licenses for files are:
> -
> -    1) CPP/7zip/Compress/Rar* files:  GNU LGPL + unRAR restriction
> -    2) All other files:  GNU LGPL

(https://git.parabola.nu/abslibre.git/tree/libre/p7zip/libre.patch#n540)

This means that we need to delete all files in (1) — for everything else
it’s just a matter of patching the files.  If I’m not mistaken this
means that deleting the files in a snippet and applying this patch on
top of it would be okay.

What do others think?

~~ Ricardo