gem sources --add http://gems.ruby-china.org/ 和gem sources --remove https://rubygems.org/都报错：ERROR: While executing gem … (Errno::EADDRNOTAVAIL)
The requested address is not valid in its context. – connect(2) for “0.0.0.0″ port 53 。网络环境DNS服务器地址自动获取改为使用下面的DNS服务器环境。ok了。
