Does not work with pytest 2.8.2 and -n > 0

[bh]

$ py.test mx/ -k acceptance/ -n0
works fine

$ py.test mx/ -k acceptance/ -n4
results in:
FFFFFFFFFFFFFFFFFFFFFFFFFFF

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
../../../.virtualenvs/mx/lib/python3.4/site-packages/pytest_bdd/scenario.py:151: in _execute_scenario
    scenario=scenario,
../../../.virtualenvs/mx/lib/python3.4/site-packages/_pytest/vendored_packages/pluggy.py:724: in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
../../../.virtualenvs/mx/lib/python3.4/site-packages/_pytest/vendored_packages/pluggy.py:338: in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

hook = <_HookCaller 'pytest_bdd_before_scenario'>, methods = [<_pytest.vendored_packages.pluggy.HookImpl object at 0x7fbeb047b320>], kwargs = {'feature': <pytest_bdd.feature.Feature object at 0x7fbe9ea01dd8>, 'request': <FixtureRequest for <Function 'test_sales_overview_modal'>>, 'scenario': <pytest_bdd.feature.Scenario object at 0x7fbe9e9fe7b8>}

    self._inner_hookexec = lambda hook, methods, kwargs: \
>       _MultiCall(methods, kwargs, hook.spec_opts).execute()
E   AttributeError: '_HookCaller' object has no attribute 'spec_opts'

../../../.virtualenvs/mx/lib/python3.4/site-packages/_pytest/vendored_packages/pluggy.py:333: AttributeError 18:44:13 

====================================================================================================================================================================== pytest-warning summary =======================================================================================================================================================================
WI2 /home/bhe/.virtualenvs/mx/lib/python3.4/site-packages/pytest_bdd/plugin.py:17 use pluginmanager.add_hookspecs instead of deprecated addhooks() method.
WI1 /home/bhe/.virtualenvs/mx/lib/python3.4/site-packages/pytest_bdd/reporting.py:147 'pytest_runtest_makereport' hook uses deprecated __multicall__ argument
WI1 /home/bhe/.virtualenvs/mx/lib/python3.4/site-packages/pytest_splinter/plugin.py:454 'pytest_runtest_makereport' hook uses deprecated __multicall__ argument

$ pip freeze | grep pytest

pytest==2.8.2
pytest-bdd==2.15.0
pytest-cov==2.1.0
pytest-django==2.8.0
-e git+https://github.com/mverteuil/pytest-ipdb.git@2b9a5a43a19d22bd16035f5fcfe9d657dc4acba3#egg=pytest_ipdb-dev
pytest-random==0.2
pytest-rerunfailures==0.5
pytest-splinter==1.7.0
pytest-xdist==1.13.1

[bh]

Ups, #149