bug#54893: guix-daemon, locale, LANG, and unicode in git tag names

[Ludovic Courtès]

Attila Lendvai <attila@lendvai.name> skribis:

> Without this the git-fetch GEXP is run in an environment that uses ASCII
> character encoding when strings are crossing the Guile - C boundary.  It means
> that e.g. tag names that have Unicode chars in them will cause problems,
> e.g. when walking and deleting the .git directory.
>
> An example in the wild: https://github.com/klauspost/pgzip/tags
>
> For more details see: https://issues.guix.gnu.org/54893
>
> * guix/git-download.scm (git-fetch): Call setlocale to set it to en_US.utf8.

I spoke a bit too fast and realized some adjustments were needed to
avoid a circular dependency on i586-gnu.  Pushed as
8852f911ff506dd50b714274ba0e2143f0285f78!

Ludo’.