anchor.diff:      export IBIS_TEST_DATA_DIRECTORY
       IBIS_TEST_DATA_DIRECTORY="$(mktemp -d)"
   
  -    # copy the test data to a writable directory
  -    cp -r ${ibisTestingData}/* "$IBIS_TEST_DATA_DIRECTORY"
  -
  -    find "$IBIS_TEST_DATA_DIRECTORY" -type d -exec chmod u+rwx {} +
  -    find "$IBIS_TEST_DATA_DIRECTORY" -type f -exec chmod u+rw {} +
  -
  -    # load data
  -    for backend in ${lib.concatStringsSep " " testBackends}; do
  -      ${python.interpreter} ci/datamgr.py load "$backend"
  -    done
  +    # copy the test data to a directory
  +    rsync --chmod=Du+rwx,Fu+rw --archive "${ibisTestingData}/" "$IBIS_TEST_DATA_DIRECTORY"
     '';
   
     postCheck = ''
  
positive.code:   ibisTestingData = fetchFromGitHub {
      owner = "ibis-project";
      repo = "testing-data";
      rev = "a88a4b3c3b54a88e7f77e59de70f5bf20fb62f19";
      sha256 = "sha256-BnRhVwPcWFwiBJ2ySgiiuUdnF4gesnTq1/dLcuvc868=";
    };
  in
  
  buildPythonPackage rec {
    pname = "ibis-framework";
    version = "3.0.2";
    format = "pyproject";
  
    disabled = pythonOlder "3.8";
  
negative.code: 
    propagatedBuildInputs = [
      atpublic
      multipledispatch
      numpy
      packaging
  