ioctl(-1, NS_GET_USERNS) = -1 EBADF (Bad file descriptor)
ioctl(1, TIOCGWINSZ, 0x7ffd8e385cf0) = -1 ENOTTY (Not a tty)
ioctl(-1, NS_GET_PARENT) = -1 EBADF (Bad file descriptor)
ioctl(-1, NS_GET_NSTYPE) = -1 EBADF (Bad file descriptor)
ioctl(-1, NS_GET_OWNER_UID, NULL) = -1 EBADF (Bad file descriptor)
ioctl(-1, NS_GET_MNTNS_ID, NULL) = -1 EBADF (Bad file descriptor)
ioctl(3, NS_GET_MNTNS_ID, [0x2]) = 0
ioctl(3, NS_GET_USERNS) = 5
ioctl(5, NS_GET_PARENT) = -1 EPERM (Operation not permitted)
ioctl(5, NS_GET_NSTYPE) = 268435456 (CLONE_NEWUSER)
ioctl(5, NS_GET_OWNER_UID, [0]) = 0
+++ exited with 0 +++
