[Mac] "psutil.ZombieProcess" error at interpreter quit with psutil==3.3.0

[fzumstein]

>>> import xlwings
>>> quit()
Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "/Users/Felix/anaconda3/anaconda/lib/python3.5/site-packages/psutil/_psosx.py", line 199, in wrapper
    return fun(self, *args, **kwargs)
  File "/Users/Felix/anaconda3/anaconda/lib/python3.5/site-packages/psutil/_psosx.py", line 238, in cmdline
    return cext.proc_cmdline(self.pid)
ProcessLookupError: [Errno 3] No such process

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/Felix/anaconda3/anaconda/lib/python3.5/site-packages/psutil/__init__.py", line 539, in name
    cmdline = self.cmdline()
  File "/Users/Felix/anaconda3/anaconda/lib/python3.5/site-packages/psutil/__init__.py", line 592, in cmdline
    return self._proc.cmdline()
  File "/Users/Felix/anaconda3/anaconda/lib/python3.5/site-packages/psutil/_psosx.py", line 209, in wrapper
    raise ZombieProcess(self.pid, self._name, self._ppid)
psutil.ZombieProcess: psutil.ZombieProcess process still exists but it's a zombie (pid=61)