nobu / ruby-lang.org wrote: > Since r63758, `rb_waitpid()` hangs up frequently (not always) on macOS (darwin17). > Seems `SIGCHLD` is not delivered. I guess sigsetjmp in r63803 did not help? I don't think it would, once a thread starts, the signal mask won't change. My polling-for-lossy-SIGCHLD implementation was incomplete, r63829 should complete it for __APPLE__. Seems like a strange kernel bug, but all the other BSDs seem fine... Only thing left is somebody to figure out the non-blocking waitpid/WaitForSingleObject [ruby-core:87759] for win32. Unsubscribe: <mailto:ruby-core-request / ruby-lang.org?subject=unsubscribe> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>