I was looking into nose2 as a way to get around the restrictions of having both xunit output and multiprocessing in nose1.3. However, when always-on is set to False in the [multiprocess] section, I can only get a single process running, while when running with always-on set to True, I get the following error: ---------------------------------------------------------------------- Ran 0 tests in 0.043s OK Traceback (most recent call last): File "C:\dev\testing\Tests\PythonTests\venv\Scripts\nose2-script.py", line 8, in <module> load_entry_point('nose2==0.4.7', 'console_scripts', 'nose2')() File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\main.py", line 284, in discover return main(*args, **kwargs) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\main.py", line 98, in __init__ super(PluggableTestProgram, self).__init__(**kw) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\unittest2-0.5.1- py2.7.egg\unittest2\main.py", line 98, in __init__ self.runTests() File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\main.py", line 260, in runTests self.result = runner.run(self.test) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\runner.py", line 53, in run executor(test, result) File "C:\dev\testing\Tests\PythonTests\venv\lib\site-packages\nose2-0.4.7-py2. 7.egg\nose2\plugins\mp.py", line 60, in _runmp ready, _, _ = select.select(rdrs, [], [], self.testRunTimeout) select.error: (10038, 'An operation was attempted on something that is not a soc ket') This is running python 2.7.5 (32bit) on Windows 7 in a virtualenv with six-1.1.0, unittest2-0.5.1 and nose2-0.4.7 (I get the same behavior outside of the venv, so I don't think that is the issue here).