anchor.diff:  
     checkInputs = [ pytestCheckHook ];
     dontUseSetuptoolsCheck = true;
  -  # following doesn't work b/c they are distributed across different nix sitePackages dirs. Tested with pytest though.
  -  pythonImportsCheck = [ "qiskit" "qiskit.circuit" "qiskit.ignis" "qiskit.providers.aer" "qiskit.aqua" ];
   
  -  meta = {
  +  pythonImportsCheck = [
  +    "qiskit"
  +    "qiskit.aqua"
  +    "qiskit.circuit"
  +    "qiskit.ignis"
  +    "qiskit.providers.aer"
  +  ];
  +
  +  meta = with lib; {
       description = "Software for developing quantum computing programs";
       homepage = "https://qiskit.org";
       downloadPage = "https://github.com/QISKit/qiskit/releases";
  -    license = lib.licenses.asl20;
  -    maintainers = with lib.maintainers; [ drewrisinger pandaman ];
  +    changelog = "https://qiskit.org/documentation/release_notes.html";
  +    license = licenses.asl20;
  +    maintainers = with maintainers; [ drewrisinger pandaman ];
     };
   }
  
positive.code: buildPythonPackage rec {
    pname = "qiskit";
    # NOTE: This version denotes a specific set of subpackages. See https://qiskit.org/documentation/release_notes.html#version-history
    version = "0.19.6";
  
    disabled = pythonOlder "3.5";
  
  
negative.code:     owner = "Qiskit";
      repo = "qiskit";
      rev = version;
      sha256 = "1r23pjnql49gczf4k4m6ir5rr95gqdxjrks60p8a93d243mxx3c9";
    };
  
    propagatedBuildInputs = [
  