While working on reproducible builds for openSUSE, I found that
our python-mailmanclient package fails to build on 1-core VMs

Steps To Reproduce:

osc co openSUSE:Factory/python-mailmanclient && cd $_
osc build -j1 --vm-type=kvm --noservice standard

Actual Results:

[  206s] ---------------------------- Captured stderr setup 
[  206s] --- Logging error ---
[  206s] Traceback (most recent call last):
[  206s]   File "/usr/lib64/python3.7/logging/handlers.py", line 933, in emit
[  206s]     self.socket.send(msg)
[  206s] OSError: [Errno 9] Bad file descriptor
[  206s]
[  206s] During handling of the above exception, another exception occurred:
[  206s]
[  206s] Traceback (most recent call last):
[  206s]   File "/usr/lib64/python3.7/logging/handlers.py", line 936, in emit
[  206s]     self._connect_unixsocket(self.address)
[  206s]   File "/usr/lib64/python3.7/logging/handlers.py", line 854, in
_connect_unixsocket
[  206s]     self.socket.connect(address)
[  206s] FileNotFoundError: [Errno 2] No such file or directory
[  206s] Call stack:
[  206s]   File "/usr/bin/py.test-3.7", line 11, in <module>
[  206s]     load_entry_point('pytest==5.3.5', 'console_scripts', 'py.test')()
...
[  206s]   File "/usr/lib/python3.7/site-packages/pluggy/callers.py", line 187,
in _multicall
[  206s]     res = hook_impl.function(*args)
[  206s]   File "/usr/lib/python3.7/site-packages/_pytest/fixtures.py", line
958, in pytest_fixture_setup
[  206s]     result = call_fixture_func(fixturefunc, request, kwargs)
[  206s]   File "/usr/lib/python3.7/site-packages/_pytest/fixtures.py", line
788, in call_fixture_func
[  206s]     res = fixturefunc(**kwargs)
[  206s]   File
"/home/abuild/rpmbuild/BUILD/mailmanclient-3.3.0/src/mailmanclient/conftest.py",
line 48, in mailman_core
[  206s]     request=request,
[  206s]   File "/usr/lib/python3.7/site-packages/pytest_services/service.py",
line 71, in watcher_getter_function 
[  206s]     services_log.debug('Starting {0}: {1}'.format(name, arguments))
[  206s] Message: "Starting master: ['-C', 'mailman_test.cfg']"
[  206s] Arguments: ()
[  206s] ============ 15 passed, 1 deselected, 1 error in 154.12s (0:02:34) 


Feel free to move upstream as you see fit.