in pathconf, -1, not 0, means unsupported.. syncio presumably works, too.
[musl] / src / network / listen.c
1 #include <sys/socket.h>
2 #include "syscall.h"
3
4 int listen(int fd, int backlog)
5 {
6         return socketcall(listen, fd, backlog, 0, 0, 0, 0);
7 }