The Internet is full of advice on how to edit XKB files and tweak your keyboard layout — under Xorg. With Wayland though, that advice didn’t quite work for me. Here are the problems I ran into, and the solutions I found.

setxkbmap -print only shows the US layout

This command is supposed to dump your entire keymap, including layouts and options, but for me, it only displayed the basic US layout:

$ setxkbmap -print

xkb_keymap {
  xkb_keycodes  { include "evdev+aliases(qwerty)" };
  xkb_types     { include "complete"      };
  xkb_compat    { include "complete"      };
  xkb_symbols   { include "pc+us+inet(evdev)"     };
  xkb_geometry  { include "pc(pc105)"     };
};

I expected to see my “ru” layout mentioned in xkb_symbols, as well as the option to toggle layouts with Alt+Space. To fix this, I had to explicitly pass in all my layouts and options, like so:

$ setxkbmap -layout us,ru -option grp:alt_space_toggle -print

xkb_keymap {
  xkb_keycodes  { include "evdev+aliases(qwerty)" };
  xkb_types     { include "complete"      };
  xkb_compat    { include "complete"      };
  xkb_symbols   { include "pc+us+ru:2+inet(evdev)+group(alt_space_toggle)" };
  xkb_geometry  { include "pc(pc105)"     };
};

Notice how xkb_symbols now correctly lists all my settings.

xkbcomp <file> $DISPLAY doesn’t affect anything

If you put the result of setxkbmap -print into a file, edit it, and run xkbcomp <file> $DISPLAY, the edits should be applied to your keyboard. However, under Wayland, xkbcomp seemingly doesn’t do anything (and prints some errors at that!)

Actually, it does do something: it changes the settings of XWayland, an X11 server that Wayland runs for backwards compatibility with Xorg. You can verify this by running xterm: as an X11 app, it’ll use XWayland, and thus the settings you introduced with xkbcomp.

How to apply a keymap to both Wayland and XWayland though? I found two ways.

Create a custom keyboard layout

This only works for the xkb_symbols section; if you want to edit anything else, see further down.

Take your edited xkb_symbols and put it in a file under ~/.config/xkb/symbols/ (you might have to create those directories first). Give the file a plain name with no extension. If in doubt, check xkeyboard-config(7) manpage to ensure there’s no clashes with existing layouts. Remember, the file should only contain the xkb_symbols section:

xkb_symbols {
    include "pc+us+ru(ruu):2+inet(evdev)+group(alt_space_toggle)"
};

Now specify that file as your layout. In Sway WM, that means tweaking your ~/.sway/config as follows (“runomi” is my file’s name):

input type:keyboard {
    xkb_layout runomi
}

As you can see, there is no need to add xkb_options to the config — the options are taken care of by the layout file. I guess you could also use this layout in Xorg now, but I didn’t test that.

Specify a complete keymap with Sway WM

If you’d like to edit not just xkb_symbols, but other sections too, you got to replace the whole keymap. I don’t know how to do it in an arbitrary environment, but here’s a recipe for Sway WM.

First, dump your current keymap into a file using setxkbmap as described above. Let’s call it ~/.Xkeymap.

Then, edit your ~/.sway/config like so:

input type:keyboard {
    xkb_file .Xkeymap
}

That’s it: your entire keymap is now defined by that single file, and you can tweak it to your heart’s content. Enjoy!