{pkgs, ...}: let
  yo = pkgs.writeText "yo.rb" ''
    require '${./nixos.rb}'

    FLAKE_PATH = "/home/collin/nixos"

    case ARGV[0]
      when "deploy", "dep"
        ssh_host = ARGV[1] or abort "must specify ssh target (host or user@host)"
        hostname = ssh_host.include?("@") ? ssh_host.split("@", 2).last : ssh_host

        store_path = Nix.build_configuration(
          flake_path: FLAKE_PATH,
          hostname: hostname,
          use_nom: true
        )
        Nix.switch_to_configuration_remote(
          store_path: store_path,
          ssh_host: ssh_host,
          use_magic_rollback: true
        )
      when "switch", "sw"
        store_path = Nix.build_configuration(
          flake_path: FLAKE_PATH,
          hostname: `hostname`.chomp,
          use_nom: true
        )
        Nix.switch_to_configuration(
          store_path: store_path,
          verb: "switch",
          sudo_cmd: "run0 --background="
        )
      when "boot"
        store_path = Nix.build_configuration(
          flake_path: FLAKE_PATH,
          hostname: `hostname`.chomp,
          use_nom: true
        )
        Nix.switch_to_configuration(
          store_path: store_path,
          verb: "boot",
          sudo_cmd: "run0 --background="
        )
      when "test"
        store_path = Nix.build_configuration(
          flake_path: FLAKE_PATH,
          hostname: `hostname`.chomp,
          use_nom: true
        )
        Nix.switch_to_configuration(
          store_path: store_path,
          verb: "test",
          sudo_cmd: "run0 --background="
        )
      when "build"
        hostname = ARGV[1] or `hostname`.chomp

        Nix.build_configuration(
          flake_path: FLAKE_PATH,
          hostname: hostname,
          use_nom: true
        )
    end
  '';

  env = pkgs.stdenv.mkDerivation {
    name = "ruby-env";
    src = ./.;

    nativeBuildInputs = [pkgs.makeWrapper];
    buildInputs = [pkgs.ruby pkgs.nix-output-monitor];
    installPhase = ''
      mkdir -p $out/bin
      makeWrapper ${pkgs.ruby}/bin/ruby $out/bin/ruby \
        --prefix PATH : ${pkgs.lib.makeBinPath [pkgs.nix-output-monitor]}
    '';
  };
in
  pkgs.writeShellScriptBin "yo" ''
    exec ${env}/bin/ruby ${yo} "$@"
  ''