aa22be179a4dfb9633089ebc7c65c6d6c18a83d5 dropped the backend setting which was used in the test, breaking evaluation of the test in the process. Kind of defeats the purpose of a test if it isn't executed before merging a change to a module…
The library does not depend on stdenv, that `stdenv` exposes `lib` is an artifact of the ancient origins of nixpkgs.