The reason for the the slow process startup time in OS11 (#349) for the ProcessPoolExecutor is the use default use of spawn as a start method on macOS (see: https://docs.python.org/3/library/multiprocessing.html). Explicitly setting the context as fork removes the issue.
The reason for the the slow process startup time in OS11 (#349) for the
ProcessPoolExecutoris the use default use ofspawnas a start method on macOS (see: https://docs.python.org/3/library/multiprocessing.html). Explicitly setting the context asforkremoves the issue.