in pathconf, -1, not 0, means unsupported.. syncio presumably works, too.
[musl] / src / unistd / getsid.c
1 #include <unistd.h>
2 #include "syscall.h"
3
4 pid_t getsid(pid_t pid)
5 {
6         return syscall(SYS_getsid, pid);
7 }