Error: TypeError: expected str, bytes or os.PathLike object, not NoneType

Sometimes i get this error:

Traceback (most recent call last):
  File "/opt/homebrew/Cellar/python@3.10/3.10.15/Frameworks/Python.framework/Versions/3.10/lib/python3.10/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/opt/homebrew/Cellar/python@3.10/3.10.15/Frameworks/Python.framework/Versions/3.10/lib/python3.10/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/opt/homebrew/lib/python3.10/site-packages/django_q/cluster.py", line 165, in __init__
    self.start()
  File "/opt/homebrew/lib/python3.10/site-packages/django_q/cluster.py", line 174, in start
    self.guard()
  File "/opt/homebrew/lib/python3.10/site-packages/django_q/cluster.py", line 315, in guard
    self.reincarnate(p)
  File "/opt/homebrew/lib/python3.10/site-packages/django_q/cluster.py", line 234, in reincarnate
    prometheus_multiprocess.mark_process_dead(process.pid)
  File "/opt/homebrew/lib/python3.10/site-packages/prometheus_client/multiprocess.py", line 169, in mark_process_dead
    for f in glob.glob(os.path.join(path, f'gauge_{mode}_{pid}.db')):
  File "/opt/homebrew/Cellar/python@3.10/3.10.15/Frameworks/Python.framework/Versions/3.10/lib/python3.10/posixpath.py", line 76, in join
    a = os.fspath(a)
TypeError: expected str, bytes or os.PathLike object, not NoneType

It happen here:

https://github.com/django-q2/django-q2/blob/337a5782d9113a6e9d058743488e7517aebb8280/django_q/cluster.py#L233-L234

When mark_process_dead is called.

Can you help me?

Thanks.

Start at django_q/cluster.py around lines 233-234 and trace the call into prometheus_client.multiprocess.mark_process_dead. Reproduce the failure and inspect why the path passed to os.path.join is None. Done means the cause is confirmed and the failing scenario has defined, verified behavior.