Cloudpickle 1.5.0, dill 0.3.2 or 0.3.1.1:

import dill
import cloudpickle


class Foo:

    def bar(self, param: int):
        hello = "Hello"
        def baz() -> None:
            print(hello, param)

        cloudpickle.loads(cloudpickle.dumps(baz))()


if __name__ == '__main__':
    Foo().bar(param=2)

This fails with ValueError: Cell is empty.

Without the dill import, or with the dill import after the cloudpickle import, and it's all fine.

If the inner function is just

        def baz() -> None:
            print("Hello world")

then it's also fine.

The problem seems to be if the inner function captures anything in its closure.

According to the cloudpickle dev cloudpipe/cloudpickle#393

In this precise case, importing dill triggers a global side effect which add a high-priority cell reducer that is not compatible with cloudpickle's way of reducing cells.

is there a way to get around this, and have both dill and cloudpickle work?