anchor.diff:    python_simple_hipchat = python-simple-hipchat; # added 2021-07-21
     qasm2image = throw "qasm2image is no longer maintained (since November 2018), and is not compatible with the latest pythonPackages.qiskit versions."; # added 2020-12-09
     requests_toolbelt = requests-toolbelt; # added 2017-09-26
  -  rotate-backups = throw "pythonPackages.rotate-backups was removed in favor of the top-level rotate-backups"; # added 2021-07-01
  +  rotate-backups = throw "rotate-backups was removed in favor of the top-level rotate-backups"; # added 2021-07-01
     scikitlearn = scikit-learn; # added 2021-07-21
     selectors34 = throw "selectors34 has been removed: functionality provided by Python itself; archived by upstream."; # added 2021-06-10
     setuptools_scm = setuptools-scm; # added 2021-06-03
  
positive.code:   smmap2 = throw "smmap2 has been deprecated, use smmap instead."; # added 2020-03-14
    sphinxcontrib_plantuml = sphinxcontrib-plantuml; # added 2021-08-02
    sqlalchemy_migrate = sqlalchemy-migrate; # added 2021-10-28
    topydo = throw "python3Packages.topydo was moved to topydo"; # added 2017-09-22
    tvnamer = throw "python3Packages.tvnamer was moved to tvnamer"; # added 2021-07-05
    WazeRouteCalculator = wazeroutecalculator; # added 2021-09-29
    websocket_client = websocket-client; # added 2021-06-15
    zc-buildout221 = zc-buildout; # added 2021-07-21
  
negative.code:   HAP-python = hap-python; # added 2021-06-01
    IMAPClient = imapclient; # added 2021-10-28
    jupyter_client = jupyter-client; # added 2021-10-15
    lammps-cython = throw "lammps-cython no longer builds and is unmaintained"; # added 2021-07-04
    MechanicalSoup = mechanicalsoup; # added 2021-06-01
    pam = python-pam; # added 2020-09-07.
    PasteDeploy = pastedeploy; # added 2021-10-07
    powerlineMemSegment = powerline-mem-segment; # added 2021-10-08
    privacyidea = throw "privacyidea has been renamed to pkgs.privacyidea"; # added 2021-06-20
    prometheus_client = prometheus-client; # added 2021-06-10
    prompt_toolkit = prompt-toolkit; # added 2021-07-22
    pylibgen = throw "pylibgen is unmaintained upstreamed, and removed from nixpkgs"; # added 2020-06-20
  