anchor.diff:  buildPythonPackage rec {
     pname = "distributed";
     version = "2.30.1";
  +  disabled = pythonOlder "3.6";
   
     # get full repository need conftest.py to run tests
     src = fetchPypi {
  
positive.code: { lib
  , buildPythonPackage
  , fetchPypi
  , pytest
  , pytest-repeat
  , pytest-timeout
  , mock
  , joblib
  , click
  , cloudpickle
  , dask
  
negative.code: , tornado
  , zict
  , pyyaml
  , mpi4py
  , bokeh
  , pythonOlder
  