[solved] Custom keyboard in GNOME - link `xkeyboard-config` to .config/xdg

JanKaifer · September 16, 2022, 4:29pm

I’m trying to use custom keyboard layout in GNOME with Wayland. My current setup is:

  # Configure keymap in X11
  services.xserver = {
    layout = "fck";
    extraLayouts.fck = {
      description = "Fancy czech keyboard";
      languages = [ "eng" "cs" ];
      symbolsFile = builtins.fetchurl {
        url = "https://gitlab.com/JanKaifer/fck/-/raw/master/cz";
      };
    };
  };

Gnome is not picking this up (I can’t select it in the settings), but I can select this layout when using X11 by doing setxkbmap, but there is no way to do it in Wayland.

There are many posts regarding this, but none of them helped me. The most relevant was this:

github.com/NixOS/nixpkgs

services.xserver.extraLayouts aren't honored by GNOME 3

opened 10:08PM - 27 Dec 19 UTC

closed 08:21PM - 28 Dec 19 UTC

lourkeur

0.kind: bug 6.topic: GNOME

**Describe the bug** Keyboard layouts added using `services.xserver.extraLayout…s` do not show up in the GNOME 3 control center. Under Xorg they can still be activated with `setxkbmap`, but not under Wayland. **To Reproduce** Steps to reproduce the behavior: 1. add a custom layout in `<nixos-config>` 2. rebuild nixos and switch to the new configuration (and relog) 3. Go to the GNOME settings under country & language, click the plus and look for the new layout. **Expected behavior** The custom layout should be available and usable. **Screenshots** If applicable, add screenshots to help explain your problem. **Additional context** The switch to Wayland is probably why GNOME is overriding the X11 defaults. The solution is to make `gsd-daemon` work for us rather than fight against it. **Metadata** Please run `nix run nixpkgs.nix-info -c nix-info -m` and paste the result. - system: `"x86_64-linux"` - host os: `Linux 4.19.91, NixOS, 19.09.1686.69ed29f5f41 (Loris)` - multi-user?: `yes` - sandbox: `yes` - version: `nix-env (Nix) 2.3` - channels(root): `"nixos-19.09.1686.69ed29f5f41"` - channels(louis): `"nixos-unstable-20.03pre206438.a06925d8c60"` - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos` Maintainer information: ```yaml # a list of nixpkgs attributes affected by the problem attribute: # a list of nixos modules affected by the problem module: ```

The fix itself mentions this PR in GNOME:

This PR says that GNOME is looking for keyboard layouts here: “$XDG_CONFIG_ROOT/xkb” this evaluates to “.config/xkb” on my machine.
When I tried looking for the layout that is generated by nix I got few packages in /nix/store with echo /**/xkb/symbols/fck.

So I tried symlinking it to ~/.config. Something like ~/.config/xkb -> /nix/store/1jb6zf1x7xkcv0p3nfnprqhh32vhkrmn-xkeyboard-config-2.33/etc/X11/xkb/.
This worked and I can see my layout in the settings.
Now I need to generate that nix store path programmatically in my config.

I tried pkgs.xkeyboard_config.outPath, but that gives me a path to a different package that doesn’t have my custom layout.

JanKaifer · September 16, 2022, 5:25pm

One dirty hack is that once I add the layout in settings (via hardcoded path to /nix/store) GNOME remembers that layout forever. I can remove that link to my /nix/store and it will continue to work.

JanKaifer · September 16, 2022, 5:30pm

Did I solve it? Maybe? Hopefully!

I had XDG_CONFIG_HOME = "$HOME/.config" in my configuration.nix.
When I removed that line it started working again. It also cleared XDG_CONFIG_ROOT.

Weird, but I don’t need those variables (those are just leftovers from my old system) so I will accept this as a solution.

lourkeur · September 16, 2022, 5:34pm

One way to do this is simply to call your layout custom. I’m not sure which package it is, but there is a package that contains a database of keyboard layouts that has a special entry for us to use like that. It should show up in GNOME.

jtojnar · September 16, 2022, 6:28pm

That is not a thing, the variable is named XKB_CONFIG_ROOT, which the extra-layouts module creates by default:

github.com

NixOS/nixpkgs/blob/b207142dcc285f985ae6419df914262debeef12a/nixos/modules/services/x11/extra-layouts.nix#L124

    
      
          
          
};
          
          
###### implementation
          
          
config = mkIf (layouts != { }) {
          
          
  environment.sessionVariables = {
              # runtime override supported by multiple libraries e. g. libxkbcommon
              # https://xkbcommon.org/doc/current/group__include-path.html
              XKB_CONFIG_ROOT = "${xkb_patched}/etc/X11/xkb";
            };
          
          
  services.xserver = {
              xkbDir = "${xkb_patched}/etc/X11/xkb";
              exportConfiguration = config.services.xserver.displayManager.startx.enable
                || config.services.xserver.displayManager.sx.enable;
            };
          
          
};

An it should contain a value like /nix/store/01qsglilnjzlczknw9zvh0gmf6h2slcp-xkeyboard-config-2.33/etc/X11/xkb.

~/.config sounds like you are confusing the variable with XDG_CONFIG_HOME (notice the prefix is named after X KeyBoard, not X Desktop Group, and the suffix is root, not home).

I would expect it to work unless there was a regression. Though it probably requires you to re-log in after you rebuild your system since it is not possible to change environment of running programs in general.

As I mentioned, the extra-layouts module already sets the variable, which is then picked up by libxkb & co.

JanKaifer · September 16, 2022, 9:32pm

I totally missed the XDG vs XKB difference.
But weirdly adding and removing “XDG_CONFIG_HOME” from my configuration.nix was adding/removing the layout from the settings.

But I tested XKB_CONFIG_ROOT and it points to the correct /nix/store/ path.

Thanks a lot for catching this obvious mistake, I was struggling with this for a few hours.