arigo@gcc2-power8:LE:~/br/otherrepo/rpython/jit/backend/test$ python ../../../../pytest.py test_zll_stress_*.py -xv
Traceback (most recent call last):
  File "../../../../pytest.py", line 33, in <module>
    raise SystemExit(pytest.main())
  File "/home/arigo/br/otherrepo/_pytest/config.py", line 39, in main
    config = _prepareconfig(args, plugins)
  File "/home/arigo/br/otherrepo/_pytest/config.py", line 118, in _prepareconfig
    pluginmanager=pluginmanager, args=args)
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 724, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 338, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 333, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 595, in execute
    return _wrapped_call(hook_impl.function(*args), self.execute)
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 249, in _wrapped_call
    wrap_controller.send(call_outcome)
  File "/home/arigo/br/otherrepo/_pytest/helpconfig.py", line 28, in pytest_cmdline_parse
    config = outcome.get_result()
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 279, in get_result
    _reraise(*ex)  # noqa
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 264, in __init__
    self.result = func()
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 596, in execute
    res = hook_impl.function(*args)
  File "/home/arigo/br/otherrepo/_pytest/config.py", line 861, in pytest_cmdline_parse
    self.parse(args)
  File "/home/arigo/br/otherrepo/_pytest/config.py", line 966, in parse
    self._preparse(args, addopts=addopts)
  File "/home/arigo/br/otherrepo/_pytest/config.py", line 927, in _preparse
    self.pluginmanager.load_setuptools_entrypoints("pytest11")
  File "/home/arigo/br/otherrepo/_pytest/vendored_packages/pluggy.py", line 495, in load_setuptools_entrypoints
    from pkg_resources import iter_entry_points, DistributionNotFound
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 72, in <module>
    import packaging.requirements
  File "/usr/lib/python2.7/site-packages/packaging/requirements.py", line 59, in <module>
    MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
TypeError: __call__() takes exactly 2 arguments (1 given)