解决gem不能使用的问题

今天尝试使用gem安装cocoaPod时，gem报错：

ERROR:  While executing gem ... (Gem::RemoteFetcher::FetchError)
    Errno::ETIMEDOUT: A connection attempt failed because the connected party di
d not properly respond after a period of time, or established connection failed
because connected host has failed to respond. - connect(2) for "rubygems.global.
ssl.fastly.net" port 443 (https://api.rubygems.org/quick/Marshal.4.8/sass-3.4.13
.gemspec.rz)


之后通过搜索找到了解决方案：
原因是ruby 的gem被和谐了，现在淘宝的ruby工程师架设了rubygems的国内镜像。使用方法如下：

$ gem sources --remove https://rubygems.org/
$ gem sources -a https://ruby.taobao.org/
$ gem sources -l
打印如下：
*** CURRENT SOURCES ***

https://ruby.taobao.org

之后就可以使用了！