pthread_sigmask(SIG_BLOCK, &set, NULL);
if (sigismember(&set, SIGPIPE))
So, the answer is, of course, it can't. However that doesn't stop
sigwait() from being used for SIGPIPE, perhaps others. Obviously
this doesn't work for SIGBUS, SIGSEGV. Well maybe it would, but
not correctly. Probably works for SIGFPE.