let
  nixpkgs = builtins.fetchTarball (import ../../pack/nixpkgs.nix);
  nixos-mailserver = builtins.fetchTarball {
    url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/v2.2.1/nixos-mailserver-v2.2.1.tar.gz";
    sha256 = "03d49v8qnid9g9rha0wg2z6vic06mhp0b049s3whccn1axvs2zzx";
  };
in
import "${nixpkgs}/nixos" {
  system = "x86_64-linux";
  configuration = {
    imports = [
      ./hardware-configuration.nix
      ./networking.nix

      # end config
      ./configuration.nix

      # our modules
      ../../mode/ibb.nix
      ../../mode/fathom.nix

      # third party
      nixos-mailserver
    ];
  };
}