鉴于：
Rails 2.3.x应用程序当前正在升级到Rails 3。
红宝石从1.8.7升级到1.9.2
Rails应用程序曾经使用mongrel作为开发的Web服务器。
全新安装的Ubuntu 10.10上网本混音。
我忘记在开始升级之前安装杂种，所以...
问题：
在更新了一些代码以使延迟的工作正常运行之后，我去运行rails s，我意识到我正在运行WEBrick。我为1.9.2版本安装了mongrel：gem install mongrel --pre并再次运行rails s。它仍在使用WEBrick，这不是预期的行为。以前，我只是安装杂种，而rails会知道我想要杂种。
另外，当运行WEBrick时，我会收到此错误...它会启动，然后出错，然后关闭。 （也许由于升级或...也许WEBrick不喜欢ruby 1.9.2？）：
=> Booting WEBrick
=> Rails 3.0.5 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/home/aaron/dev/onlinescheduler/config/initializers/new_rails_defaults.rb:14:in `<top (required)>': undefined method `generate_best_match=' for ActionDispatch::Routing:Module (NoMethodError)
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:235:in `load'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:235:in `block in load'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:225:in `block in load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:596:in `new_constants_in'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:225:in `load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:235:in `load'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/engine.rb:201:in `block (2 levels) in <class:Engine>'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/engine.rb:200:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/engine.rb:200:in `block in <class:Engine>'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/initializable.rb:25:in `instance_exec'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/initializable.rb:25:in `run'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/initializable.rb:50:in `block in run_initializers'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/initializable.rb:49:in `each'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/initializable.rb:49:in `run_initializers'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/application.rb:134:in `initialize!'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/application.rb:77:in `method_missing'
from /home/aaron/dev/onlinescheduler/config/environment.rb:5:in `<top (required)>'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:239:in `require'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:239:in `block in require'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:225:in `block in load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:596:in `new_constants_in'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:225:in `load_dependency'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:239:in `require'
from /home/aaron/dev/onlinescheduler/config.ru:3:in `block in <main>'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/builder.rb:46:in `instance_eval'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/builder.rb:46:in `initialize'
from /home/aaron/dev/onlinescheduler/config.ru:1:in `new'
from /home/aaron/dev/onlinescheduler/config.ru:1:in `<main>'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/builder.rb:35:in `eval'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/builder.rb:35:in `parse_file'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/server.rb:162:in `app'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/server.rb:248:in `wrapped_app'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/rack-1.2.1/lib/rack/server.rb:213:in `start'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands/server.rb:65:in `start'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:30:in `block in <top (required)>'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:27:in `tap'
from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.5/lib/rails/commands.rb:27:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
最佳答案
如果您添加它会更好
group :development do
gem :mongrel
end
因为您在生产中不需要它