https://rubygems.org/
今天看到了如下的提示:
Warning: You‘re using Rubygems 1.8.23.2 with Spring. Upgrate to at least Rubygems 2.1.0 and run Rails 4.1.4
$gem update --system
update to the latest RubyGems version
原文：http://www.cnblogs.com/iwangzheng/p/3951501.html