Monkey-patching to override Pickle Serializer (not recommended + error-prone)

dill_multiprocessing.py

# pip install dill
import io

import dill as pickle
from weakref import WeakSet
from multiprocessing import reduction


class ForkingPickler(reduction.ForkingPickler):
    loads = pickle.loads

    @classmethod
    def dumps(cls, obj, protocol=None):
        buf = io.BytesIO()
        pickle.dump(obj, buf)
        return buf.getbuffer()


reduction.pickle = pickle
reduction.ForkingPickler = ForkingPickler
reduction.dump = pickle.dump

# where the program begins
from multiprocessing import Process


def execute(param=None):
    print(param, type(param))


if __name__ == "__main__":
    test = WeakSet()

    process = Process(target=execute, args=(test,))
    process.start()
    process.join()