pledge()'s 2nd argument becomes char *execpromises, which becomes the

pledge()'s 2nd argument becomes char *execpromises, which becomes the
pledge for a new execve image immediately upon start.  Also introduces
"error" which makes violations return -1 ENOSYS instead of killing the
program ("error" may not be handed to a setuid/setgid program, which
may be missing/ignoring syscall return values and would continue with
inconsistant state)
Discussion with many
florian has used this to improve the strictness of a daemon