使用命令 gem sources -a https://ruby.taobao.org/

提示以下信息：

Error fetching https://ruby.taobao.org/:
        SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed (https://rubygems-china.oss-cn-hangzhou.aliyuncs.com/specs.4.8.gz)