[bug#42180] bug#51061: [PATCH v2 01/23] guix: Add extracting-download.

[Ludovic Courtès]

Hartmut Goebel <h.goebel@crazy-compilers.com> skribis:

> * guix/build-system/rebar3.scm, guix/build/rebar3-build-system.scm: New files.
> * Makefile.am (MODULES): Add them.

This looks OK, except it’s undocumented:

  https://guix.gnu.org/manual/en/html_node/Build-Systems.html

I’d be in favor of reverting until we can see the doc.

Also, I would have suggested not adding new build systems on ‘master’:
they’ll have to be adjusted on ‘core-updates-frozen’, and I’d rather
distribute the workload on this and avoid merge issues.

> +;;; GNU Guix --- Functional package management for GNU
> +;;; Copyright © 2016 Ricardo Wurmus <rekado@elephly.net>

Is Ricardo involved?

> +    (for-each
> +     (lambda (pkg)
> +       (for-each
> +        (lambda (dirname)
> +          (let ((src-dir (string-append build-dir "/" pkg "/" dirname))
> +                (dst-dir (string-append pkg-dir "/" dirname)))
> +            (when (file-exists? src-dir)
> +              (copy-recursively src-dir dst-dir #:follow-symlinks? #t))
> +            (false-if-exception
> +             (delete-file (string-append dst-dir "/.gitignore")))))
> +        '("ebin" "include" "priv")))

Regarding the style, please avoid abbreviations: ‘source’, not
‘src-dir’, etc.

  https://guix.gnu.org/manual/en/html_node/Formatting-Code.html

The root of a package directory should follow the usual layout: bin,
sbin, share, lib, libexec.  I think we should not have “ebin” and
“priv”, unless there’s a very good justification.

Thanks,
Ludo’.