As noted in #2511, `sem_init()` is not implemented on MacOS; some other methods should be used. See e.g. * https://stackoverflow.com/questions/1413785/sem-init-on-os-x * https://stackoverflow.com/questions/641126/posix-semaphores-on-mac-os-x-sem-timedwait-alternative (sample fallback implem available)
As noted in #2511,
sem_init()is not implemented on MacOS; some other methods should be used. See e.g.