Map CAPS LOCK to CTRL on hold and to ESC on tap on NixOS

Put this into your configuration.nix file. This is layout neutral.

  
    services.interception-tools =
    let
    itools = pkgs.interception-tools;
    itools-caps = pkgs.interception-tools-plugins.caps2esc;
    in
    {
    enable = true;
    plugins = [ itools-caps ];
    # requires explicit paths: https://github.com/NixOS/nixpkgs/issues/126681
    udevmonConfig = pkgs.lib.mkDefault ''
    - JOB: "${itools}/bin/intercept -g $DEVNODE |
    ${itools-caps}/bin/caps2esc -m 1 | ${itools}/bin/uinput -d
    $DEVNODE"
    DEVICE:
    EVENTS:
    EV_KEY: [KEY_CAPSLOCK, KEY_ESC]
    '';
    };