anchor.diff: -{ lib, stdenv
  +{ lib
  +, stdenv
   , buildPythonPackage
  -, fetchurl
  +, fetchFromGitHub
   , cffi
   , pkgs
   }:
  
positive.code:   pname = "pyspotify";
    version = "2.1.3";
  
    src = fetchurl {
      url = "https://github.com/mopidy/pyspotify/archive/v${version}.tar.gz";
      sha256 = "1y1zqkqi9jz5m9bb2z7wmax7g40c1snm3c6di6b63726qrf26rb7";
    };
  
    propagatedBuildInputs = [ cffi ];
  
negative.code:   doCheck = false;
  
    meta = with lib; {
      homepage = "http://pyspotify.mopidy.com";
      description = "A Python interface to Spotify’s online music streaming service";
      license = licenses.unfree;
      maintainers = with maintainers; [ lovek323 ];
      platforms = platforms.unix;
    };
  
  }
  