gem sources --add http://gems.ruby-china.org/ 和gem sources --remove https://rubygems.org/都報錯：ERROR: While executing gem … (Errno::EADDRNOTAVAIL)
The requested address is not valid in its context. – connect(2) for “0.0.0.0″ port 53 。網絡環境DNS服務器地址自動獲取改為使用下面的DNS服務器環境。ok了。
