anchor.diff:  { stdenv
   , lib
   , buildPythonPackage
  -, fetchFromGitHub
  +, fetchPypi
   , pythonOlder
  -
   , asdf
   , astropy
   , astropy-helpers
  +, astropy-extension-helpers
   , beautifulsoup4
   , drms
   , glymur
  
positive.code: 
  buildPythonPackage rec {
    pname = "sunpy";
    version = "1.0.6";
    disabled = pythonOlder "3.6";
  
    src = fetchFromGitHub {
      owner = "sunpy";
      repo = pname;
      rev = "v${version}";
      sha256 = "0j2yfhfxgi95rig8cfp9lvszb7694gq90jvs0xrb472hwnzgh2sk";
    };
  
    propagatedBuildInputs = [
      numpy
  
negative.code:     pytest-mock
    ];
  
    # darwin has write permission issues
    doCheck = stdenv.isLinux;
    # ignore documentation tests
    checkPhase = ''
      PY_IGNORE_IMPORTMISMATCH=1 HOME=$(mktemp -d) pytest sunpy -k 'not rst'
    '';
  
    meta = with lib; {
  