static void extract_user_namespace(ProcessHandle sandbox) {
	// test user namespaces available in the kernel
	struct stat self_userns;
	if (stat("/proc/self/ns/user", &self_userns) != 0)
		return;

	// check sandbox user namespace
	struct stat dest_userns;
	process_stat(sandbox, "ns/user", &dest_userns);

	if (dest_userns.st_ino != self_userns.st_ino ||
	    dest_userns.st_dev != self_userns.st_dev)
		arg_noroot = 1;
}
static void extract_user_namespace(ProcessHandle sandbox) {
	 
	struct stat self_userns;
	if (stat("/proc/self/ns/user", &self_userns) != 0)
		return;

	 
	struct stat dest_userns;
	process_stat(sandbox, "ns/user", &dest_userns);

	if (dest_userns.st_ino != self_userns.st_ino ||
	    dest_userns.st_dev != self_userns.st_dev)
		arg_noroot = 1;
}