nixpkgs/lib/tests/modules/declare-mkPackageOption.nix

{ lib, ... }: let
  pkgs.hello = {
    type = "derivation";
    pname = "hello";
  };
in {
  options = {
    package = lib.mkPackageOption pkgs "hello" { };

    namedPackage = lib.mkPackageOption pkgs "Hello" {
      default = [ "hello" ];
    };

    namedPackageSingletonDefault = lib.mkPackageOption pkgs "Hello" {
      default = "hello";
    };

    pathPackage = lib.mkPackageOption pkgs [ "hello" ] { };

    packageWithExample = lib.mkPackageOption pkgs "hello" {
      example = "pkgs.hello.override { stdenv = pkgs.clangStdenv; }";
    };

    packageWithPathExample = lib.mkPackageOption pkgs "hello" {
      example = [ "hello" ];
    };

    packageWithExtraDescription = lib.mkPackageOption pkgs "hello" {
      extraDescription = "Example extra description.";
    };

    undefinedPackage = lib.mkPackageOption pkgs "hello" {
      default = null;
    };

    nullablePackage = lib.mkPackageOption pkgs "hello" {
      nullable = true;
      default = null;
    };

    nullablePackageWithDefault = lib.mkPackageOption pkgs "hello" {
      nullable = true;
    };

    packageWithPkgsText = lib.mkPackageOption pkgs "hello" {
      pkgsText = "myPkgs";
    };

    packageFromOtherSet = let myPkgs = {
      hello = pkgs.hello // { pname = "hello-other"; };
    }; in lib.mkPackageOption myPkgs "hello" { };
  };
}