Mac OS X EI Capitan系统下cocoapods无法安装

系统升级到Mac OS X EI Capitan后，使用命令：sudo gem install cocoapods，安装cocoapods，出现以下错误：

ERROR:Could not find a valid gem 'cocoapods' (>= 0), here is why:Unable to download data from http://ruby.taobao.org/ - bad response Not Found 404 (http://ruby.taobao.org/latest_specs.4.8.gz)

解决方法：

1.  gem sources --remove http://ruby.taobao.org/

2.  gem sources -a https://ruby.taobao.org/

再次尝试：sudo gem install cocoapods，出现新的错误：

ERROR:While executing gem ... (Errno::EPERM)

Operation not permitted - /usr/bin/xcodeproj

解决方法：

sudo gem install -n /usr/local/bin cocoapods

OK!