ENOTSOCK
ATF_REQUIRE_ERRNO(ENOTSOCK, listen(fdc, 1) == -1);
case ENOTSOCK:
error = ENOTSOCK;
error = ENOTSOCK;
return (ENOTSOCK);
error = ENOTSOCK;
error = ENOTSOCK;
error = ENOTSOCK;
error = ENOTSOCK;