gem source -l
如果显示：
* CURRENT SOURCES *
https://ruby.taobao.org/
移除
sudo gem install cocoapods
ERROR: While executing gem … (OpenSSL::SSL::SSLError)
hostname “upyun.gems.ruby-china.org” does not match the server certificate
gem sources –remove https://ruby.taobao.org/
gem sources -a https://gems.ruby-china.org
sudo gem update –system
sudo gem install -n /usr/local/bin cocoapods –pre
pod –version
1.2.1
更新成功
提示错误：
ERROR: While executing gem ... (URI::InvalidURIError)
bad URI(is not URI?): ?gems=–pre
执行pod setup
参考：http://www.cnblogs.com/i-am-lvjiazhen/p/6136502.html
https://www.2cto.com/kf/201705/639919.html
