gem install报错,这是怎么了?

walkermyy

E:\>gem install rails -V
Error fetching remote data:             SocketError: getaddrinfo:
(https://ruby.taobao.org/latest_specs.4.8.gz)
Falling back to local-only install
ERROR:  Could not find a valid gem 'rails' (>= 0) in any repository
ERROR:  While executing gem ... (Gem::RemoteFetcher::FetchError)
    SocketError: getaddrinfo:   (https://ruby.taobao.org/lates
t_specs.4.8.gz)