xdist is incompatible with built-in pytest maxfail argument

[taliastocks]

Steps to reproduce:

• Create test_deleteme.py in an otherwise empty directory (e.g. /tmp/deleteme):

import time

def test_0 ():
    assert False

def test_1 ():
    time.sleep(1)

def test_2 ():
    pass

def test_3 ():
    pass

def test_4 ():
    pass

• Change to the test directory (cd /tmp/deleteme).
• Run py.test -x -n2 or py.test --maxfail=1 -n2.

The output should show that one test has failed, and it does. However, it should not show INTERNALERROR>. See the full output:

/tmp/deleteme$ py.test -x -n2
================================================ test session starts ================================================
platform linux2 -- Python 2.7.9, pytest-2.9.1, py-1.4.31, pluggy-0.3.1
rootdir: /tmp/deleteme, inifile: 
plugins: xdist-1.14
gw0 [5] / gw1 [5]
scheduling tests via LoadScheduling
FINTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/main.py", line 94, in wrap_session
INTERNALERROR>     session.exitstatus = doit(config, session) or 0
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/main.py", line 125, in _main
INTERNALERROR>     config.hook.pytest_runtestloop(session=session)
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 724, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 338, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 333, in <lambda>
INTERNALERROR>     _MultiCall(methods, kwargs, hook.spec_opts).execute()
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 596, in execute
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "<remote exec>", line 49, in pytest_runtestloop
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/execnet/gateway_base.py", line 737, in receive
INTERNALERROR>     raise self._getremoteerror() or EOFError()
INTERNALERROR> EOFError
INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/main.py", line 94, in wrap_session
INTERNALERROR>     session.exitstatus = doit(config, session) or 0
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/main.py", line 125, in _main
INTERNALERROR>     config.hook.pytest_runtestloop(session=session)
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 724, in __call__
INTERNALERROR>     return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 338, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook, methods, kwargs)
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 333, in <lambda>
INTERNALERROR>     _MultiCall(methods, kwargs, hook.spec_opts).execute()
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/_pytest/vendored_packages/pluggy.py", line 596, in execute
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "<remote exec>", line 49, in pytest_runtestloop
INTERNALERROR>   File "/usr/local/lib/python2.7/dist-packages/execnet/gateway_base.py", line 737, in receive
INTERNALERROR>     raise self._getremoteerror() or EOFError()
INTERNALERROR> EOFError

===================================================== FAILURES ======================================================
______________________________________________________ test_0 _______________________________________________________
[gw0] linux2 -- Python 2.7.9 /usr/bin/python
def test_0 ():
>       assert False
E       assert False

test_deleteme.py:5: AssertionError
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================= 1 failed in 1.55 seconds ==============================================

[nicoddemus]

Yes, that's certainly annoying. Thanks for the report!

[taliastocks]

You're able to reproduce the issue by following my steps? I'm sorry that I wasn't able to come up with a simpler example, but this one reproduced the error pretty consistently for me. Let me know if you need any more information.

[nicoddemus]

I didn't try, but I've seen it happen if memory serves correctly. 😁