anchor.diff:      owner = "Qiskit";
       repo = "qiskit-ignis";
       rev = version;
  -    sha256 = "07mxhaknkp121xm6mgrpcrbj9qw6j924ra3k0s6vr8qgvfcxvh0y";
  +    sha256 = "17kplmi17axcbbgw35dzfr3d5bzfymxfni9sf6v14223c5674p4y";
     };
  +
  +  # hacky, fix https://github.com/Qiskit/qiskit-ignis/issues/532.
  +  # TODO: remove on qiskit-ignis v0.5.1
  +  postPatch = ''
  +    substituteInPlace qiskit/ignis/mitigation/expval/base_meas_mitigator.py --replace "plt.axes" "'plt.axes'"
  +  '';
   
     propagatedBuildInputs = [
       numpy
       qiskit-terra
       scikitlearn
       scipy
  -  ];
  -  postInstall = "rm -rf $out/${python.sitePackages}/docs";  # this dir can create conflicts
  +  ] ++ lib.optionals (withCvx) [ cvxpy ]
  +  ++ lib.optionals (withVisualization) [ matplotlib ]
  +  ++ lib.optionals (withJit) [ numba ];
  +  postInstall = "rm -rf $out/${python.sitePackages}/docs"; # this dir can create conflicts
   
     # Tests
     pythonImportsCheck = [ "qiskit.ignis" ];
  
positive.code: , qiskit-terra
  , scikitlearn
  , scipy
    # Check Inputs
  , pytestCheckHook
  , ddt
  
negative.code:   ];
    disabledTests = [
      "test_tensored_meas_cal_on_circuit" # Flaky test, occasionally returns result outside bounds
      "test_qv_fitter" # execution hangs, ran for several minutes
    ];
  
    meta = with lib; {
  