Using freezegun during threaded function causes an odd error

[datacubed]

with freeze_time('2023-01-01 12:00:00+00:00'):
    my_model.value += 1
    my_model.save(update_fields=['value'])

I get this error: "'_freeze_time' object has no attribute 'fake_names'"

And this stacktrace:

my_model.save(update_fields=['value'])
  File "/usr/local/lib/python3.8/dist-packages/freezegun/api.py", line 616, in __exit__
    self.stop()
  File "/usr/local/lib/python3.8/dist-packages/freezegun/api.py", line 741, in stop
    if module_attribute in self.fake_names:

Looking at the code it seems like self.fake_names is never populated, and maybe that start() is not called?

[markddavidoff]

+1 also having this issue.

[pnajman-modoolar]

+1 I have this issue as well.

[markddavidoff]

I ended up adding a setup sync step in my test code, where each thread does a serialized setup before being used for concurrent test code.

[pnajman-modoolar]

@markddavidoff

I'm afraid I don't understand what you mean by that.

[markddavidoff]

You can create a wrapper function when freezing time in threads which wraps the freeze time call with a lock instead of calling freeze time directly. This force your threads to only freeze time one at a time.

[mangelozzi]

You can create a wrapper function when freezing time in threads which wraps the freeze time call with a lock instead of calling freeze time directly. This force your threads to only freeze time one at a time.

Could you please share a code snippet demonstrating your fix?