builder for fontconfig-conf fails on unstable

[romildo]

Describe the bug

When rebuilding my NixOS unstable system I am getting the following failure:

[...]
rm: cannot remove '/nix/store/pqxvjd0gmx9y8q91r4vr72m03l4gwx19-fontconfig-conf/etc/fonts/2.11/conf.d/50-user.conf': No such file or directory
builder for '/nix/store/ph3kzyfmyg7jzqfjxfqkblwqmy8dgvj5-fontconfig-conf.drv' failed with exit code 1
cannot build derivation '/nix/store/x8hqsd8hssd2nsbwywgv7pnbsc94832y-fontconfig-etc.drv': 1 dependencies couldn't be built
cannot build derivation '/nix/store/s82vqjm59l8vwflly5i4isj7xd00y654-etc.drv': 1 dependencies couldn't be built
cannot build derivation '/nix/store/zfxa5z84pyglzfkzq0g0i04z0n84gsww-nixos-system-romildo-20.09pre238896.16fc531784a.drv': 1 dependencies couldn't be built
error: build of '/nix/store/zfxa5z84pyglzfkzq0g0i04z0n84gsww-nixos-system-romildo-20.09pre238896.16fc531784a.drv' failed

Metadata

• system: "x86_64-linux"
• host os: Linux 5.7.14, NixOS, 20.09.git.6ecf3768a5e (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(root): "nixos-20.09pre238896.16fc531784a"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

[DIzFer]

To save someone the bisect, the culprit seems to be f527651

[flokli]

Even with nixpkgs pointed precisely at 16fc531784a (what this nixpkgs checkout seems to be at), I can't reproduce.

[flokli]

I also tried building nixos/tests/gnome3.nix, which surely should pull in fontconfig.

[pbogdan]

Same failure as romildo if I set fonts.fontconfig.includeUserConf to false. If I set it to true... #95712

[DIzFer]

On 17/08/2020 21:48, pbogdan wrote: Same failure as romildo if I set `fonts.fontconfig.includeUserConf` to `false`. If I set it to true... #95712

Yes, I forgot to add that the line in question seems to imply that option triggers the `rm` command that fails. More specifically, in nixos/modules/config/fonts/fontconfig.nix, I can build my system if I comment out lines 207 to 209.

[romildo]

Same failure as romildo if I set fonts.fontconfig.includeUserConf to false. If I set it to true... #95712

I have this set to false on my system.

[flokli]

It seems I missed parts of edf2541 while rebasing #93562. Fix incoming.

[flokli]

Should be fixed by #95716.