constraints.txt

# This is a pip constraints file that is used to preserve Python 2.6
# compatibility (on Travis CI). Why I'm still doing that in 2018 is
# a good question, maybe simply to prove that I can :-P.

# flake8 3.0.0 drops explicit support for Python 2.6:
# http://flake8.pycqa.org/en/latest/release-notes/3.0.0.html
flake8 < 3.0.0 ; python_version < '2.7'

# flake8-docstrings 1.0.0 switches from pep257 to pydocstyle and I haven't been
# able to find a combination of versions of flake8-docstrings and pydocstyle
# that actually works on Python 2.6. Here's the changelog:
# https://gitlab.com/pycqa/flake8-docstrings/blob/master/HISTORY.rst
flake8-docstrings < 1.0.0 ; python_version < '2.7'

# pyflakes 2.0.0 drops Python 2.6 compatibility:
# https://github.com/PyCQA/pyflakes/blob/master/NEWS.txt
pyflakes < 2.0.0 ; python_version < '2.7'

# pytest 3.3 drops Python 2.6 compatibility:
# https://docs.pytest.org/en/latest/changelog.html#pytest-3-3-0-2017-11-23
pytest < 3.3 ; python_version < '2.7'

# pytest-cov 2.6.0 drops Python 3.4 compatibility:
# https://pytest-cov.readthedocs.io/en/latest/changelog.html
pytest-cov < 2.6.0 ; python_version < '3.5'

# attrs 16.0.0 (used by pytest) drops Python 2.6 compatibility:
# http://www.attrs.org/en/stable/changelog.html
attrs < 16.0.0 ; python_version < '2.7'

# pycparser < 2.19 drops Python 2.6 compatibility:
# https://github.com/eliben/pycparser/blob/master/CHANGES
pycparser < 2.19 ; python_version < '2.7'

# idna 2.8 drops Python 2.6 compatibility (not documented).
idna < 2.8 ; python_version < '2.7'