anchor.diff: -{ lib, pkgs, buildPythonPackage, fetchPypi, isPy3k, callPackage
  +{ lib, buildPythonPackage, fetchPypi, isPy3k
   , opencv3
   , pyqt5
   , pyqtgraph
  
positive.code: , imageio-ffmpeg
  , av
  , nose
  , pytest
  , pyserial
  , arrayqueues
  , colorspacious
  
negative.code:     inherit pname version;
      sha256 = "aab9d07575ef599a9c0ae505656e3c03ec753462df3c15742f1f768f2b578f0a";
    };
  
    # crashes python
    preCheck = ''
      rm stytra/tests/test_z_experiments.py
    '';
  
    checkInputs = [
      nose
      pytestCheckHook
      pyserial
    ];
  
    propagatedBuildInputs = [
      opencv3
  