2020
https://www.reddit.com/r/NixOS/comments/j93u78/custom_xmonadhs_ignored_defaults_to_plain_xterm/

    windowsManager = {
        xmonad.enable = true;
        xmonad.enableContribAndExtras = true;
        xmonad.extraPackages = hpkgs: [
            hpkgs.xmonad
            hpkgs.xmonad-contrib
            hpkgs.xmonad-extras
        ];
    };
    ...
    xmobar
    nitrogen
    picom
    dmenu

modularized-config
https://github.com/kanashimia/nixos/tree/mistress/modules/window-managers/xmonad
https://github.com/kanashimia/nixos/blob/mistress/modules/window-managers/xmonad/default.nix