我是ruby和rails的新手，我正在创建一个应用程序，我已经实现了一些代码并尝试将其上传到Heroku。代码已经部署，但是当我尝试访问该页面时，它会显示Application Error页面。
我在日志中看到以下内容：
2014-09-04T14:42:50.478707+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands.rb:55:in `block in <top (required)>'
2014-09-04T14:42:50.478419+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2014-09-04T14:42:50.478452+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `block in require'
2014-09-04T14:42:50.478575+00:00 app[web.1]: from /app/config.ru:in `<main>'
2014-09-04T14:42:50.478540+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
2014-09-04T14:42:50.478691+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands/server.rb:70:in `start'
2014-09-04T14:42:50.478154+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:359:in `require_or_load'
2014-09-04T14:42:50.478505+00:00 app[web.1]: from /app/config.ru:3:in `block in <main>'
2014-09-04T14:42:50.478625+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/server.rb:200:in `app'
2014-09-04T14:42:50.478402+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/railtie/configurable.rb:30:in `method_missing'
2014-09-04T14:42:50.478469+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:236:in `load_dependency'
2014-09-04T14:42:50.478522+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
2014-09-04T14:42:50.478674+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/server.rb:254:in `start'
2014-09-04T14:42:50.478723+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands.rb:50:in `tap'
2014-09-04T14:42:50.473154+00:00 app[web.1]: => Call with -d to detach
2014-09-04T14:42:50.473153+00:00 app[web.1]: => Rails 3.2.19 application starting in production on
2014-09-04T14:42:50.476663+00:00 app[web.1]: Exiting
2014-09-04T14:42:50.478740+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands.rb:50:in `<top (required)>'
2014-09-04T14:42:50.478756+00:00 app[web.1]: from script/rails:6:in `require'
2014-09-04T14:42:50.478772+00:00 app[web.1]: from script/rails:6:in `<main>'
2014-09-04T14:42:51.726468+00:00 heroku[web.1]: State changed from starting to crashed
2014-09-04T14:42:51.719828+00:00 heroku[web.1]: Process exited with status 1
2014-09-05T04:56:06.809647+00:00 heroku[web.1]: State changed from crashed to starting
2014-09-05T04:56:14.406322+00:00 heroku[web.1]: Starting process with command `bundle exec rails server thin -p 50156 -e production`
2014-09-05T04:56:15.594411+00:00 app[web.1]: Your Gemfile lists the gem pg (>= 0) more than once.
2014-09-05T04:56:15.594425+00:00 app[web.1]: You should probably keep only one of them.
2014-09-05T04:56:15.594427+00:00 app[web.1]: While it's not a problem now, it could cause errors if you change the version of just one of them later.
2014-09-05T04:56:18.552965+00:00 app[web.1]: DEPRECATION WARNING: You have Rails 2.3-style plugins in vendor/plugins! Support for these plugins will be removed in Rails 4.0. Move them out and bundle them in your Gemfile, or fold them in to your app as lib/myplugin/* and config/initializers/myplugin.rb. See the release notes for more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called from <top (required)> at /app/config/environment.rb:5)
2014-09-05T04:56:18.553754+00:00 app[web.1]: DEPRECATION WARNING: You have Rails 2.3-style plugins in vendor/plugins! Support for these plugins will be removed in Rails 4.0. Move them out and bundle them in your Gemfile, or fold them in to your app as lib/myplugin/* and config/initializers/myplugin.rb. See the release notes for more on this: http://weblog.rubyonrails.org/2012/1/4/rails-3-2-0-rc2-has-been-released. (called from <top (required)> at /app/config/environment.rb:5)
2014-09-05T04:56:19.550825+00:00 app[web.1]: [deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
2014-09-05T04:56:21.017207+00:00 app[web.1]: => Booting Thin
2014-09-05T04:56:21.017215+00:00 app[web.1]: => Ctrl-C to shutdown server
2014-09-05T04:56:21.017212+00:00 app[web.1]: => Rails 3.2.19 application starting in production on "http://:50156"
2014-09-05T04:56:21.017217+00:00 app[web.1]: Exiting
2014-09-05T04:56:21.018178+00:00 app[web.1]: /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require': /app/app/models/contact.rb:4: syntax error, unexpected keyword_end (SyntaxError)
2014-09-05T04:56:21.018191+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:359:in `require_or_load'
2014-09-05T04:56:21.017214+00:00 app[web.1]: => Call with -d to detach
2014-09-05T04:56:21.018195+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:502:in `load_missing_constant'
2014-09-05T04:56:21.018197+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:192:in `block in const_missing'
2014-09-05T04:56:21.018183+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `block in require'
2014-09-05T04:56:21.018226+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.19/lib/action_controller/metal/params_wrapper.rb:169:in `_set_wrapper_defaults'
2014-09-05T04:56:21.018200+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:190:in `each'
2014-09-05T04:56:21.018205+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/inflector/methods.rb:230:in `block in constantize'
2014-09-05T04:56:21.018209+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/inflector/methods.rb:229:in `each'
2014-09-05T04:56:21.018212+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/inflector/methods.rb:229:in `constantize'
2014-09-05T04:56:21.018239+00:00 app[web.1]: from /app/app/controllers/contacts_controller.rb:1:in `<top (required)>'
2014-09-05T04:56:21.018185+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:236:in `load_dependency'
2014-09-05T04:56:21.018251+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
2014-09-05T04:56:21.018219+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/core_ext/string/inflections.rb:66:in `safe_constantize'
2014-09-05T04:56:21.018234+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.19/lib/abstract_controller/railties/routes_helpers.rb:7:in `block (2 levels) in with'
2014-09-05T04:56:21.018230+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.19/lib/action_controller/metal/params_wrapper.rb:133:in `inherited'
2014-09-05T04:56:21.018223+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.19/lib/action_controller/metal/params_wrapper.rb:152:in `_default_wrap_model'
2014-09-05T04:56:21.018237+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/actionpack-3.2.19/lib/action_controller/railties/paths.rb:7:in `block (2 levels) in with'
2014-09-05T04:56:21.018242+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
2014-09-05T04:56:21.018287+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/initializable.rb:30:in `instance_exec'
2014-09-05T04:56:21.018260+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:225:in `require_dependency'
2014-09-05T04:56:21.018289+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/initializable.rb:30:in `run'
2014-09-05T04:56:21.018216+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/inflector/methods.rb:260:in `safe_constantize'
2014-09-05T04:56:21.018265+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/engine.rb:443:in `each'
2014-09-05T04:56:21.018254+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:359:in `require_or_load'
2014-09-05T04:56:21.018290+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/initializable.rb:55:in `block in run_initializers'
2014-09-05T04:56:21.018306+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `block in require'
2014-09-05T04:56:21.018189+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
2014-09-05T04:56:21.018201+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:190:in `const_missing'
2014-09-05T04:56:21.018263+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/engine.rb:444:in `block (2 levels) in eager_load!'
2014-09-05T04:56:21.018298+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/application.rb:136:in `initialize!'
2014-09-05T04:56:21.018319+00:00 app[web.1]: from /app/config.ru:in `new'
2014-09-05T04:56:21.018344+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands.rb:50:in `tap'
2014-09-05T04:56:21.018269+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/engine.rb:443:in `block in eager_load!'
2014-09-05T04:56:21.018286+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/application/finisher.rb:53:in `block in <module:Finisher>'
2014-09-05T04:56:21.018314+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
2014-09-05T04:56:21.018246+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `block in require'
2014-09-05T04:56:21.018280+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/engine.rb:441:in `each'
2014-09-05T04:56:21.018299+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/railtie/configurable.rb:30:in `method_missing'
2014-09-05T04:56:21.018322+00:00 app[web.1]: from /app/config.ru:in `<main>'
2014-09-05T04:56:21.018247+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:236:in `load_dependency'
2014-09-05T04:56:21.018285+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/engine.rb:441:in `eager_load!'
2014-09-05T04:56:21.018312+00:00 app[web.1]: from /app/config.ru:3:in `block in <main>'
2014-09-05T04:56:21.018304+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
2014-09-05T04:56:21.018327+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:40:in `parse_file'
2014-09-05T04:56:21.018301+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2014-09-05T04:56:21.018324+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:40:in `eval'
2014-09-05T04:56:21.018346+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands.rb:50:in `<top (required)>'
2014-09-05T04:56:21.018311+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:251:in `require'
2014-09-05T04:56:21.018333+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/server.rb:304:in `wrapped_app'
2014-09-05T04:56:21.018352+00:00 app[web.1]: from script/rails:6:in `<main>'
2014-09-05T04:56:21.018328+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/server.rb:200:in `app'
2014-09-05T04:56:21.018256+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:313:in `depend_on'
2014-09-05T04:56:21.018296+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/initializable.rb:54:in `run_initializers'
2014-09-05T04:56:21.018317+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
2014-09-05T04:56:21.018341+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands.rb:55:in `block in <top (required)>'
2014-09-05T04:56:21.018292+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/initializable.rb:54:in `each'
2014-09-05T04:56:21.018307+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.19/lib/active_support/dependencies.rb:236:in `load_dependency'
2014-09-05T04:56:21.018331+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands/server.rb:46:in `app'
2014-09-05T04:56:21.018337+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.19/lib/rails/commands/server.rb:70:in `start'
2014-09-05T04:56:21.018336+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/server.rb:254:in `start'
2014-09-05T04:56:21.018349+00:00 app[web.1]: from script/rails:6:in `require'
2014-09-05T04:56:21.807475+00:00 heroku[web.1]: Process exited with status 1
2014-09-05T04:56:21.819265+00:00 heroku[web.1]: State changed from starting to crashed
2014-09-05T12:38:06.227862+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=blooming-mountain-5811.herokuapp.com request_id=a661a3b1-2ce0-4aaa-b5d4-339ba724f759 fwd="94.201.235.75" dyno= connect= service= status=503 bytes=
2014-09-05T12:38:07.175574+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=blooming-mountain-5811.herokuapp.com request_id=c9faaccc-2ea4-4977-affe-7ad78b293e30 fwd="94.201.235.75" dyno= connect= service= status=503 bytes=
答案 0 :(得分：0)
有几件事：
2014-09-05T04:56:15.594411+00:00 app[web.1]: Your Gemfile lists the gem pg (>= 0) more than once.
2014-09-05T04:56:15.594425+00:00 app[web.1]: You should probably keep only one of them.
您需要从pg中删除对Gemfile gem的重复提及。我不知道如何为你的 Gemfile做到这一点，因为我看不到它。你是这里的老板。
接下来，正如评论中提到的，您的Contact模型存在语法错误。你需要解决这个问题。