When I tried to delivered the playwright tasks via celery==4.4.7, I got an AttributeError exception at line 50 in main.py.

except AttributeError:

I've checked the source from pytest, the original code is:

    except (AttributeError, io.UnsupportedOperation):
           # pytest-xdist monkeypatches sys.stderr with an object that is not an actual file.
           # https://docs.python.org/3/library/faulthandler.html#issue-with-file-descriptors
           # This is potentially dangerous, but the best we can do.
           return sys.__stderr__.fileno()

It perfectly works if I changed it to the original code, so I think we should be consistent with the original source code to enhance compatibility.

I also checked the celery official docs. The reason why I got an AttributeError exception probably is that the log proxy of celery is not support the stderr attribute.