anchor.diff:  { lib
   , buildPythonPackage
   , fetchPypi
  -, fetchpatch
   , nose
   , scikitlearn
   , scipy
  
positive.code:     numba
      llvmlite
      joblib
    ];
  
    checkPhase = ''
  
negative.code: 
  buildPythonPackage rec {
    pname = "pynndescent";
    version = "0.5.2";
  
    src = fetchPypi {
      inherit pname version;
      sha256 = "0w87c2v0li2rdbx6qfc2lb6y6bxpdy3jwfgzfs1kcr4d1chj5zfr";
    };
  
    propagatedBuildInputs = [
      scikitlearn
  