Bring your towel and join one of the fastest growing data communities. Welcome to our second-generation open source orchestration platform, a completely rethought approach to dataflow automation.

Prefect Community

Hi, is anyone familiar with this error? :
``````

No

I don't think this is the answer you were looking for but you asked a YES/NO question and you didn't give enough information to say more :smile: could you perhaps explain when/how did you encounter this error? what flow did you run? was it with the latest version?

and please could you move the code block into the thread to keep the main channel clean? Thanks in advance!

```--- Orion logging error ---
The log worker encountered a fatal error.
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/prefect/logging/handlers.py", line 82, in _send_logs_loop
    anyio.run(self.send_logs)
  File "/usr/local/lib/python3.9/site-packages/anyio/_core/_eventloop.py", line 70, in run
    return asynclib.run(func, *args, **backend_options)
  File "/usr/local/lib/python3.9/site-packages/anyio/_backends/_asyncio.py", line 292, in run
    return native_run(wrapper(), debug=debug)
  File "/usr/local/lib/python3.9/asyncio/runners.py", line 47, in run
    _cancel_all_tasks(loop)
  File "/usr/local/lib/python3.9/asyncio/runners.py", line 56, in _cancel_all_tasks
    to_cancel = tasks.all_tasks(loop)
  File "/usr/local/lib/python3.9/asyncio/tasks.py", line 54, in all_tasks
    tasks = list(_all_tasks)
  File "/usr/local/lib/python3.9/_weakrefset.py", line 65, in __iter__
    for itemref in self.data:
RuntimeError: Set changed size during iteration
Worker information:
    Approximate queue length: 0
    Pending log batch length: 0
    Pending log batch size: 0```


thank you. I have posted this error hoping that maybe it is something known  :wink:
I will try to provide more details today

It is prefect2.0 (2.0b7)
I rerun the same flow again and now it finished without errors :confused:
From the above logs  I would suspect that it was some problem in prefect's logging mechanism, but maybe not...
Yesterday I got this error but Flows/Tasks succeeded, so it is not something very harmful

I will try to reproduce it but I don't know if I will be able to...

No worries, thanks for providing more context. And I encourage you to upgrade to 2.0b8, tons of amazing new features there including Blocks