[bug#52799] [PATCH] gnu: guile-udev: Update to 0.2.1

[Mathieu Othacehe]

Hey Artyom,

You may prefer to use AC_PATH_PROG to locate guile_snarf, you can have a
look the configure.ac file of Guile-Avahi for instance.

> +     `(#:phases (modify-phases %standard-phases
> +                  (add-after 'unpack 'patch
> +                    (lambda* (#:key inputs outputs #:allow-other-keys)
> +                      (substitute* "build-aux/am/snarf"
> +                        (("\\$\\(shell whereis guile-snarf \\| cut -d' ' 
> -f2\\)")
> +                         (format #f "~a/bin/guile-snarf"
> +                                 (assoc-ref inputs "guile")))))))))

Otherwise, outputs seems to be unused in this snippet. We also now try
to avoid relying on inputs labels. So using "search-input-file" or
(string-append #$(this-package-input guile) "/bin/snarf") would be
preferred.

You can have a look to:
https://guix.gnu.org/en/blog/2021/the-big-change/ for more details.

Thanks,

Mathieu