nixos/system/desktop/plasma.nix

{ pkgs, ... }:
{
  imports = [ ./default.nix ];
  environment = {
    plasma6.excludePackages = with pkgs.kdePackages; [ plasma-browser-integration ];
    sessionVariables.QT_QPA_PLATFORM = "wayland";
  };
  services = {
    displayManager.sddm = {
      enable = true;
      wayland.enable = true;
    };
    desktopManager.plasma6 = {
      enable = true;
      enableQt5Integration = true;
    };
  };
}