bug#48331: Emacs' describe-package doesn't work for packages managed by guix

[Andrew Tropin]

> the "-pkg\\.el$" exclude might have existed for a reason
> (I don't know which, put perhaps byte compilation).

Perhaps it should be ignored during byte compilation, but still
installing it seems to be a good idea.  Ok, let's wait for Maxim answer.

> I know people take package.el for granted nowadays, but alternative
> package managers for Emacs have their uses.  This is not just a Guix
> thing :)

Why not take it for granted?)  It's built-in since 24(?), elpa/melpa
archives respect it format and provide package descriptions in -pkg.el
format, AFAIK.  Most other package managers seem to respect
"infrastructure" provided by package.el. For example you can view a list
of packages with `list-packages` even for packages installed with other
PMs (Nix for example), BTW they keep "package.el" directory structure.
https://0x0.st/-BxL.txt

Don't see too many reasons not to follow this format.

I mean it's easily fixable with current directory structure just by
stripping "/elpa" suffix from package-directory-list, but why we would
do that emacs "customization" instead of just placing packages under /elpa
subdirectory and make everything work out of the box?

> I don't think we want to fake elpa that hard.  Two iterations ago it
> was .guix.d and people didn't really like it.

Do you mean the package installation path was site-lisp/.guix.d/NAME-VERSION?

> My subdirs.el patch is also stretching it.

Not sure what you mean by this, sorry, I'm not native speaker and
automated translation doesn't make sense to me.  Rephrase please.

I do not insist on any particular directory structure, just curious why
not to stick to the widely adopted format.  Once again, thank you for placing
packages into subdirectories, now the site-lisp structure seems more
organized and less polluted + problem with describe-package (C-h P) and
list-packages are easily fixable.  Appreciate your work!)

-- 
Best regards,
Andrew Tropin