运行 bundle exec cucumber 时出现此错误。这是 Rails 版本错误吗？如何检查正在使用的 rails 是否在 Rails::Application::RoutesReloader 类中定义了此方法，以查看是否需要升级/降级？如果没有，有人有什么建议吗？
编辑：
堆栈跟踪：
undefined method `paths' for #<Rails::Application::RoutesReloader:0xac73454> (NoMethodError)
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/engine.rb:517:in `block in <class:Engine>'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:25:in `instance_exec'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:25:in `run'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:50:in `block in run_initializers'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:49:in `each'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:49:in `run_initializers'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/application.rb:92:in `initialize!'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-rails-1.3.0/lib/cucumber/rails/application.rb:15:in `initialize!'
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
/home/ubuntu/hw3_rottenpotatoes/config/environment.rb:5:in `<top (required)>'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-rails-1.3.0/lib/cucumber/rails.rb:7:in `require'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-rails-1.3.0/lib/cucumber/rails.rb:7:in `<top (required)>'
/home/ubuntu/hw3_rottenpotatoes/features/support/env.rb:7:in `require'
/home/ubuntu/hw3_rottenpotatoes/features/support/env.rb:7:in `<top (required)>'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/rb_support/rb_language.rb:129:in `load'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/rb_support/rb_language.rb:129:in `load_code_file'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:171:in `load_file'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:83:in `block in load_files!'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:82:in `each'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/runtime/support_code.rb:82:in `load_files!'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/runtime.rb:175:in `load_step_definitions'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/runtime.rb:40:in `run!'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/cli/main.rb:43:in `execute!'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/lib/cucumber/cli/main.rb:20:in `execute'
/usr/local/lib/ruby/gems/1.9.1/gems/cucumber-1.2.1/bin/cucumber:14:in `<top (required)>'
/usr/local/bin/cucumber:19:in `load'
/usr/local/bin/cucumber:19:in `<main>'
我认为这是 rails 的错误，因为当我尝试运行 rails 服务器时，它给了我同样的错误。安装一定发生了什么事，因为该命令之前运行没有问题