rails-2.3.5和rack-1.0.1的来源在哪里？(Where are the sources for rails-2.3.5 and rack-1.0.1?)

 我正在尝试升级需要rails-2.3.5的rails应用程序，而这似乎需要rack-1.0.1。 以下各项的许多（很多！）尝试都没有奏效： 
 
# gem install rails -v=2.3.5
ERROR:  could not find gem rails locally or in a repository
 
 要么 
 
# gem install rails -v=2.3.5 --source http://gems.rubyforge.org
WARNING:  RubyGems 1.2+ index not found for:
    http://gems.rubyforge.org/

RubyGems will revert to legacy indexes degrading performance.
Bulk updating Gem source index for: http://gems.rubyforge.org/
ERROR:  While executing gem ... (Gem::RemoteSourceException)
    Error fetching remote gem cache: SocketError: getaddrinfo: Name or service not known (http://gems.rubyforge.org/yaml)
 
 或者用http://gems.rubyonrails.org代替。 当我尝试http://gems.github.org时，我收到索引错误。 
 
 简单地尝试gems update rails成功作为命令，但它安装版本2.3.3。 
 
 为什么这些都不起作用？ 
 
 以供参考： 
 
# cat /root/.gemrc
---
:benchmark: false
:verbose: true
:update_sources: true
:sources:
- http://gems.rubyonrails.org
- http://gems.opscode.com
:bulk_threshold: 1000
:backtrace: false
 
 （安装程序真的是版本2吗？） 

I'm trying to upgrade a rails application which requires rails-2.3.5 which in turn seems to require rack-1.0.1. Many (many!) attempts of each of the following hasn't worked: 
 
# gem install rails -v=2.3.5
ERROR:  could not find gem rails locally or in a repository
 
or
 
# gem install rails -v=2.3.5 --source http://gems.rubyforge.org
WARNING:  RubyGems 1.2+ index not found for:
    http://gems.rubyforge.org/

RubyGems will revert to legacy indexes degrading performance.
Bulk updating Gem source index for: http://gems.rubyforge.org/
ERROR:  While executing gem ... (Gem::RemoteSourceException)
    Error fetching remote gem cache: SocketError: getaddrinfo: Name or service not known (http://gems.rubyforge.org/yaml)
 
or substituting http://gems.rubyonrails.org. When I tried http://gems.github.org I get an index error.
 
Simply trying a gems update rails succeeds as a command, but it installs version 2.3.3. 
 
Why would any of this not be working?
 
For reference:
 
# cat /root/.gemrc
---
:benchmark: false
:verbose: true
:update_sources: true
:sources:
- http://gems.rubyonrails.org
- http://gems.opscode.com
:bulk_threshold: 1000
:backtrace: false
 
(Is the installer really at version 2?)