Function Pickling: 'NoneType' has no attribute __bool__ #2291
Description
The seems to be a issue with distributed being able to pickle functions with certain type hints (Union & Optional from my usage).
Here's an example:
from typing import Optional
from distributed import Client
def f2() -> Optional[int]:
return 1
def f1() -> int:
return 1
def main():
client = Client()
print(client.submit(f1).result()) # works. prints 1
print(client.submit(f2).result()) # fail. raises
client.close()
if __name__ == '__main__':
main()distributed.worker - WARNING - Could not deserialize task
Traceback (most recent call last):
File ".../distributed/worker.py", line 1385, in add_task
self.tasks[key] = _deserialize(function, args, kwargs, task)
File ".../distributed/worker.py", line 801, in _deserialize
function = pickle.loads(function)
File ".../distributed/protocol/pickle.py", line 59, in loads
return pickle.loads(x)
AttributeError: type object 'NoneType' has no attribute '__bool__'
Traceback (most recent call last):
File ".../scratches/scratch_7.py", line 22, in <module>
main()
File ".../scratches/scratch_7.py", line 17, in main
print(client.submit(f2).result())
File ".../distributed/client.py", line 195, in result
six.reraise(*result)
File ".../six.py", line 692, in reraise
raise value.with_traceback(tb)
File ".../distributed/protocol/pickle.py", line 59, in loads
return pickle.loads(x)
AttributeError: type object 'NoneType' has no attribute '__bool__'