https://ruby.taobao.org/
淘宝的源已经不再维护
更换源为腾讯的https://gems.ruby-china.org/
但是执行
gem sources --remove http://ruby.taobao.org/
gem sources -l
gem sources -a http://gems.ruby-china.org/
之后出现了问题
Error fetching http://gems.ruby-china.org/:
bad response Not Found 404 (https://gems.ruby-china.org/specs.4.8.gz)
打开https://gems.ruby-china.org/
一看,WTF