Subject: Re: bug#30435: libreoffice: Fonts don't show up after install

From: Ludovic Courtès <[email-masked]>
Date: Thu, 02 Apr 2020 17:46:00 +0200

Hi,

Pierre Neidhardt <[email-masked]> skribis:

> Running
>
> fc-cache -fv
>
> fixes the issue.
>
> Should we run this command in a profile hook?

Profile hooks are normal derivations; as such, they don’t have access to
anything but their dependencies and their output(s).

There’s currently no infrastructure to run arbitrary code upon package
installation (which I think is a feature more than a bug :-)).  We could
make an exception, but it’s kinda ugly.

I wonder if, instead, we could have Fontconfig realize that the cache is
stale somehow.

Alternately, we could generate the cache in a profile hook and have
Fontconfig use that cache instead of the one in ~/.cache.  However,
Fontconfig would need to be able to:

  1. Be told which cache to use, not just the one from ~/.guix-profile,
     so that it works equally well with other profiles.

  2. Merge several caches, so it can also account for fonts installed in
     /run/current-system/profile.

We discussed all this several times in the past but I don’t think it
went further.

Ludo’.