我的Rails版本是3.0.4.rc1和ruby 1.9.3p194
我面临着非常奇怪的问题。
在我的项目中，我得到ERROR NoMethodError: undefined method has_key？' for nil：NilClass in development.log file and浏览器中的内部服务器错误未定义方法has_key?' for nil:NilClass。
对于任何错误，如果其无效语句，未定义变量，引发，退出，错误的数据库名称..或其他任何内容，我只收到上述错误消息。令人沮丧的是，我无法知道错误是什么或错误在哪里（行号和文件名）。
如果没有错误，它可以正常工作，但是当出现任何错误（引发，退出或任何其他错误）时，它会显示相同的错误消息。即undefined method has_key？'为零：NilClass`
错误日志：
[2013-04-19 14:41:07] ERROR NoMethodError: undefined method `has_key?' for nil:NilClass
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.0.4.rc1/lib/active_support/whiny_nil.rb:48:in `method_missing'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.2.5/lib/rack/runtime.rb:20:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.0.4.rc1/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.2.5/lib/rack/lock.rb:13:in `block in call'
<internal:prelude>:10:in `synchronize'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.2.5/lib/rack/lock.rb:13:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.0.4.rc1/lib/action_dispatch/middleware/static.rb:30:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.0.4.rc1/lib/rails/application.rb:168:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.0.4.rc1/lib/rails/application.rb:77:in `method_missing'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.0.4.rc1/lib/rails/rack/log_tailer.rb:14:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.2.5/lib/rack/content_length.rb:13:in `call'
/home/shweta/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.2.5/lib/rack/handler/webrick.rb:52:in `service'
/home/shweta/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
/home/shweta/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
/home/shweta/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
this states that such issue arises when there is a syntax error in model，但我的模型文件很好。
请帮忙。
P.S。我在rails console中没有这个问题。