**pip_check_requirements** (list, optional, ``[click==7.0, pip-tools==4.0.0, pip==19.2.3, setuptools==41.2.0, six==1.12.0, wheel==0.33.6]``)

  List of Python package requirements to install in Python 2 virtual

  environment in order to be able to run the ``pip-tools``

  applications as part of pip requirements upgrade checks. This list

  needs to be updated from time to time as the new releases of

  ``pip-tools`` and related packages are coming out. For Python 3, see

  the dedicatd parameter ``pip_check_requirements_py3`` below.

**pip_check_requirements_py3** (list, optional, ``[click==7.0, pip-tools==3.9.0, pip==19.1.1, setuptools==41.2.0, six==1.12.0, wheel==0.33.6]``)

  List of Python package requirements to install in Python 3 virtual

  environment in order to be able to run the ``pip-tools``

  applications as part of pip requirements upgrade checks. This list

  needs to be updated from time to time as the new releases of

  ``pip-tools`` and related packages are coming out. For Python 2, see

  the dedicatd parameter ``pip_check_requirements`` above.

  Take note that on Debian Jessie and Stretch there will be

  differences in what the system uses because of differing Python 3

  versions and deprecation around Python 3 minor version releases. The

  listed defaults are conservative on the side of being usable on both

  Debian Jessie and Debian Stretch as of time of this writing. For

  Debian Stretch machines you will most likely end up updating the

  list almost immediatelly.