Ruby on rails 错误：找不到有效的gem'；libxml-ruby'；（>；=0）

我有一个rails应用程序，我复制到我的机器上。我在访问应用程序时遇到以下错误

    MissingSourceFile (no such file to load -- xml):
    app/controllers/results_controller.rb:6
    /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
    /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
    /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
    /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:162:in `start'
    /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
   /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:95:in `start'
   /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:92:in `each'
   /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:92:in `start'
   /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:23:in `start'
   /usr/local/rvm/rubies/ruby-1.8.7-head/lib/ruby/1.8/webrick/server.rb:82:in `start'

我尝试安装libxml，但出现以下错误：

  [root@localhost log]# gem install libxml-ruby
  WARNING:  RubyGems 1.2+ index not found for:
  RubyGems will revert to legacy indexes degrading performance.
  ERROR:  Could not find a valid gem 'libxml-ruby' (>= 0) in any repository
  [root@localhost log]#

如何解决这个问题

Rails版本：2.3.8 Ruby版本：1.8.7

---

操作系统：FC18

该错误意味着用户拥有的gem源无法解析

libxml ruby

libxml-ruby

似乎也由托管。因此，您可以添加

https://rubygems.org

下载源代码并安装gem

# gem sources -a https://rubygems.org
https://rubygems.org added to sources

然后安装

libxml-ruby

：

# gem install libxml-ruby

这将成功安装gem

为了查看可用源的列表，您可以发布

gem sources

：

# gem sources