The role of posix_spawn is for spawning "helper processes", not starting new process groups. This should overwhelming be your common launch case. posix_spawn is

The role of posix_spawn is for spawning "helper processes", not starting new process groups. This should overwhelming be your common launch case. posix_spawn is so much faster (on BSD/Mac anyway) that fork should be outright avoided. Processes requiring other permissions can/should be spawned by asking systemd/chron/init/launchd to launch them for you.