{ config, lib, pkgs, ... }: { programs.mpv = { enable = true; package = pkgs.emptyDirectory; scripts = [ pkgs.mpvScript ]; }; test.stubs = { mpv = { extraAttrs.override = { ... }: pkgs.emptyDirectory; }; mpvScript = { extraAttrs = { scriptName = "something"; }; }; }; test.asserts.assertions.expected = [ '' The programs.mpv "package" option is mutually exclusive with "scripts" option.'' ]; }