[bug#51179] [PATCH] gnu: Add yt-dlp.

[Robin Templeton <robin@terpri.org>]

Liliana Marie Prikler <liliana.prikler@gmail.com> writes:

> Hi Robin,
>
> when pasting other stuff into a patch, one usually ought to do so after
> the "---" line before the summary and the first diff.

Ah, thanks for the reminder, it's been a minute since I used email for
patch submissions :) So IIUC, it's preferable to write:

> * gnu/packages/video.scm (yt-dlp): New variable. [...]
> ---
> 
> [RANDOM COMMENTS HERE]
> 
>  gnu/packages/video.scm | 61
> ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 61 insertions(+)

rather than using "cut here" lines and the like.

> Am Mittwoch, den 13.10.2021, 08:46 -0400 schrieb Robin Templeton:
>> Liliana Marie Prikler <liliana.prikler@gmail.com> writes:
>> 
>> [...]
>> > > +              (snippet
>> > > +               '(begin
>> > > +                  ;; Delete the pre-generated files, except for
>> > > the man page
>> > > +                  ;; which requires 'pandoc' to build.
>> [...]
>> > Is this the same as for youtube-dl?  If not, we might want to give
>> > pandoc as native-input.  That will increase build times, but it
>> > ought not to increase closure size.
>> 
>> This is analogous to youtube-dl's pandoc avoidance; IMHO youtube-dl
>> ought to use pandoc as a native input, but I wanted to keep the
>> packaging as close to youtube-dl's as possible.
> Hence why I asked whether youtube-dl does the same.  Making that change
> would probably be out of scope for now.

+1

>> [...]
>> > > +                  (add-before 'build 'build-generated-files
>> > > +                    (lambda _
>> > > +                      ;; Avoid the make targets that require
>> > > pandoc.
>> > > +                      (invoke "make"
>> > > +                              "PYTHON=python"
>> > > +                              "yt-dlp"
>> > > +                              ;;"youtube-dl.1"   ; needs pandoc
>> > > +                              "completions")))
>> > > +                  (add-before 'install 'fix-the-data-directories
>> > > +                    (lambda* (#:key outputs #:allow-other-keys)
>> > > +                      (let ((prefix (assoc-ref outputs "out")))
>> > > +                        (substitute* "setup.py"
>> > > +                          (("'etc/")
>> > > +                           (string-append "'" prefix "/etc/"))
>> > > +                          (("'share/")
>> > > +                           (string-append "'" prefix
>> > > "/share/")))
>> > > +                        #t))))))
>> > Horizontal space is at a premium and you can save some.
>> 
>> I'm not sure where exactly this should use fewer columns, but I
>> squeezed the make invocation onto a single line.
> You fixed it by accident, given that you're now required to use
> substitute-keyword-arguments*, putting #:phases on an extra line as it
> ought to be.

Oh, I see what you meant now, thanks for clarifying.

>> v2 also adds three inputs needed for the program to run correctly
>> (updated based on efraim's yt-dlp package, <https://bpa.st/FJDA>;; in
>> that package, the extra libraries are propagated inputs, but adding
>> them as regular inputs appears to be sufficient).
> Can we somehow verify that this is indeed the case?  Normally we would
> wrap PYTHONPATH in such a case.

python-build-system wraps the yt-dlc script correctly, although (as
jgart explained to me on IRC) the Python library inputs would need to
become propagated inputs if users or future packages want to use yt-dlc
as a library.

Morgan's patch packages yt-dlc the way I'd package *youtube-dl* (using a
git origin, generating the manpage with pandoc, etc.) but yt-dlc doesn't
inherit from youtube-dl in their patch. The non-downloading-related part
of yt-dlc's test suite (~10% of tests) *does* run without failures,
unlike youtube-dl, so I enabled tests and added the pytest invocation
from Morgan's version; otherwise, no changes in v3 (besides using the
latest yt-dlc release), which I'll post as a follow-up.

I don't have a strong opinion about my patch vs. Morgan's for an initial
version; at some point I think youtube-dl should be packaged similarly
to Morgan's approach, which would allow the yt-dlc definition to be
simplified too, but my patch is written to inherit from youtube-dl as
it's packaged now. IMO the order of the changes doesn't matter much.

Thanks,
Robin

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