{ config
, pkgs
, ...
}: {
  programs.zsh =
    {
      enable = true;
      enableBashCompletion = true;
      promptInit = "";
    }
    // (
      # Either of these will call `compinit`, causing >2s startup time
      # Do it in home-manager instead
      if pkgs.stdenv.isDarwin
      then {
        enableCompletion = false;
      } else {
        enableGlobalCompInit = false;
      }
    );
  environment.shells = with pkgs; [
    zsh
    fish
  ];
  programs.fish = {
    enable = true;
  };
  users.users.alan.shell = pkgs.fish;
}