The documentation of threading.excepthook (https://docs.python.org/3.8/library/threading.html#threading.excepthook) talks about "object", when it only has a "thread" attribute:

"Storing object using a custom hook can resurrect it if it is set to an object which is being finalized. Avoid storing object after the custom hook completes to avoid resurrecting objects."

I believe this is a copy and paste error from sys.unraisablehook.