Ruby on rails $gem安装rails失败。有解决办法吗？

由于某些原因，我在OSX Lion上安装Rails时遇到问题

在RVM下安装

$ gem install rails
ERROR:  While executing gem ... (Gem::RemoteFetcher::FetchError)
    bad response Forbidden 403 (http://production.cf.rubygems.org/gems/rdoc-3.12.gem)

$ gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 1.8.12
  - RUBY VERSION: 1.9.3 (2011-10-30 patchlevel 0) [x86_64-darwin11.2.0]
  - INSTALLATION DIRECTORY: /Users/ethan/.rvm/gems/ruby-1.9.3-p0@mtc_apps
  - RUBY EXECUTABLE: /Users/ethan/.rvm/rubies/ruby-1.9.3-p0/bin/ruby
  - EXECUTABLE DIRECTORY: /Users/ethan/.rvm/gems/ruby-1.9.3-p0@mtc_apps/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-darwin-11
  - GEM PATHS:
     - /Users/ethan/.rvm/gems/ruby-1.9.3-p0@mtc_apps
     - /Users/ethan/.rvm/gems/ruby-1.9.3-p0@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
     - :sources => ["http://gemcutter.org", "http://gems.rubyforge.org/", "http://gems.github.com"]
     - "install" => "--no-rdoc --no-ri"
     - "update" => "--no-rdoc --no-ri"
  - REMOTE SOURCES:
     - http://gemcutter.org
     - http://gems.rubyforge.org/
     - http://gems.github.com

---

有人看到这个吗？知道如何让它工作吗？

看起来rubygems服务器出现了暂时性问题。
我现在无法更新我的宝石。

---

过一段时间，从几分钟到几小时，再试一次。

实际上，它似乎在我系统的rdoc上特别挂断了。所以我把gem下载到我的桌面上，用

$ gem install --local ~/Desktop/rdoc-3.12.gem

然后Rails的安装就可以完成了