Cocoapods在OS X Yosemite上报错的解决方法

今天升级了Mac OS X 10.10-Yosemite以后运行pod install遇到下面的错误： 

/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:245:

in 'mkdir': Permission denied - /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-14 (Errno::EACCES)

一番折腾后找到解决方案如下：

1. 分别执行下面命令卸载cocoapods和xcodeproj，如果你的机器上面有多个版本，选择All versions卸载 
   $ sudo gem uninstall cocoapods

   $ sudo gem uninstall xcodeproj

2. 分别执行下面命令安装xcodeproj和cocoapods 
   $ sudo gem install xcodeproj

   $ sudo gem install cocoapods

接下来尝试执行pod install，如果您还遇到下面的错误

Error loading the plugin with path '/Library/Ruby/Gems/2.0.0/gems/cocoapods-plugins-0.3.1/lib/cocoapods_plugin.rb'.Errno::EACCES - Permission denied - /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-14

运行命令$ gem update --system即可。

Hope this helps, 
Michael