Multiprocessing, as implemented in differential geometry computations via

sage: Parallelism().set(nproc=8)

does not work under macOS. This has been reported by many users, a recent report being https://groups.google.com/d/msg/sage-support/0RsGgb3lmZg/zNTMFLH9AQAJ

Note there is no issue within the doctest framework, i.e. the doctests involving parallel computations implemented in src/sage/manifolds/differentiable and src/sage/tensor/modules are passed on macOS machines.

Component: performance

Keywords: multiprocessing, parallelization, macOS

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/29755