NixOS 20.09 + lxqt -- apps cannot find fonts

Help
1

I just upgraded my small lxqt installation to 20.09 and there are many apps that crash and segfault because they cannot find fonts.

$ thunderbird &

Fontconfig warning: “/etc/fonts/2.11/fonts.conf”, line 5: unknown element “description”
Fontconfig error: “/etc/fonts/2.11/fonts.conf”, line 5: invalid attribute ‘domain’
Fontconfig warning: “/etc/fonts/conf.d/10-hinting-slight.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/10-scale-bitmap-fonts.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/20-unhint-small-vera.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/30-metric-aliases.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/40-nonlatin.conf”, line 4: unknown element “description”

$ calibre &

Fontconfig warning: “/etc/fonts/2.11/fonts.conf”, line 5: unknown element “description”
Fontconfig error: “/etc/fonts/2.11/fonts.conf”, line 5: invalid attribute ‘domain’
Fontconfig warning: “/etc/fonts/conf.d/10-hinting-slight.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/10-scale-bitmap-fonts.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/20-unhint-small-vera.conf”, line 4: unknown element “description”
Fontconfig warning: “/etc/fonts/conf.d/30-metric-aliases.conf”, line 4: unknown element “description”

Calibre is Qt but Thunderbird is GTK. Chromium and all the lxqt desktop utils so far seem to work.

Any insight about this?
Thanks in advance, alcofribas

2

Did you update your nix-env installed packages as well? Programs from 20.09 should not access /etc/fonts/2.11. You might also need to remove ~/.cache/fontconfig after you update everything.

3

Yeah, that’s what it was. And I fancied myself as not a beginner anymore…
NixOS takes a while to sink in, especially when you don’t use it that often.

Thanks a lot Jan

4

this was very much a one-off with fontconfig having a non-backwards compatible change.

5

There’s something to be said for putting everything in /etc/nixos/configuration.nix, especially when you’re lousy at keeping a log.