报错如下：

Undefined symbols for architecture x86_64:

  "___darwin_check_fd_set_overflow", referenced from:

      socket_gethostbyname(char const, socket_ipinfo_t, int, char const, NetCheckTrafficMonitor) in mars(dnsquery.o)

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

这个是什么错误？