One thing I haven't seen any blogs write about is that multiprocessing in 3.8.x uses `spawn()` and not `fork()`[0] on MacOS. Granted, most applications are not

One thing I haven't seen any blogs write about is that multiprocessing in 3.8.x uses `spawn()` and not `fork()`[0] on MacOS. Granted, most applications are not running on OS X Server, but an update that changes a low level API like that led to some issues where running code locally will fail when running it remotely will work. The following code will run anywhere except on MacOS on 3.8.x, where it crashes with `_pickle.PicklingError` as it tries to resolve the name `func` that is not in the new stack: import multiprocessing some_data = {1: "one", 2: "two"} func = lambda: some_data.get(2) process = multiprocessing.Process(target=func) process.start() [0]: https://bugs.python.org/issue33725 https://bugs.python.org/issue33725