pytest --version (return code: 0)
This is pytest version 3.1.3, imported from /usr/lib/python2.7/dist-packages/pytest.pyc
pytest -H (return code: 2)
usage: pytest [options] [file_or_dir] [file_or_dir] [...]
pytest: error: unrecognized arguments: -H
inifile: None
rootdir: /tmp/sandpit