nixos-config/modules/home/waybar/waybar.nix

{ pkgs, ... }: 
{
  programs.waybar = {
    enable = true;
  };
  programs.waybar.package = pkgs.waybar.overrideAttrs (oa: {
    mesonFlags = (oa.mesonFlags or [ ]) ++ [ "-Dexperimental=true" ];
  });
}