anchor.diff:      inherit pname version;
     };
   
  -  checkInputs = [ pytest psutil ] ++ lib.optionals isPy3k [
  -    imageio-ffmpeg ffmpeg_3
  -    ];
  -  propagatedBuildInputs = [ numpy pillow ];
  +  propagatedBuildInputs = [
  +    imageio-ffmpeg
  +    numpy
  +    pillow
  +  ];
   
  -  checkPhase = ''
  +  checkInputs = [
  +    psutil
  +    pytestCheckHook
  +  ];
  +
  +  preCheck = ''
       export IMAGEIO_USERDIR="$TMP"
       export IMAGEIO_NO_INTERNET="true"
       export HOME="$(mktemp -d)"
  -    py.test
  -  '';
  -
  -  # For some reason, importing imageio also imports xml on Nix, see
  -  # https://github.com/imageio/imageio/issues/395
  -
  -  # Also, there are tests that test the downloading of ffmpeg if it's not installed.
  -  # "Uncomment" those by renaming.
  -  postPatch = ''
  -    substituteInPlace tests/test_meta.py --replace '"urllib",' "\"urllib\",\"xml\","
  -    substituteInPlace tests/test_ffmpeg.py --replace 'test_get_exe_installed' 'get_exe_installed'
     '';
   
     meta = with lib; {
  
positive.code:     homepage = "http://imageio.github.io/";
      license = licenses.bsd2;
    };
  
  }
  
negative.code: { lib
  , buildPythonPackage
  , isPy27
  , fetchPypi
  , imageio-ffmpeg
  , numpy
  , pillow
  , psutil
  , pytestCheckHook
  }:
  
  buildPythonPackage rec {
  