安装cocoapods时已经替换成淘宝镜像依然无法成功:ERROR: Could not find a valid gem 'cocoapods' (>= 0), here is why:

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)
是因为淘宝停止基于 HTTP 协议的镜像服务
需要改用https的协议：

gem sources --remove http://ruby.taobao.org/ 
gem sources -a https://ruby.taobao.org/ 
gem sources -l

sudo gem install cocoapods

然后就可以继续使用cocoapods了。