类用户的超类不匹配（TypeError）？答案

【问题标题】：Superclass mismatch for class User (TypeError)?类用户的超类不匹配（TypeError）？
【发布时间】：2013-12-13 23:32:56
【问题描述】：

我在使用 Heroku 时遇到了麻烦。我做了heroku logs 并收到一条错误消息：

/app/app/models/user.rb:1:in `<top (required)>': superclass mismatch for class User     (TypeError)

/app/app/models/user.rb:1:in `<top (required)>': superclass mismatch for class User     (TypeError)

2013-11-28T03:39:50.220378+00:00 app[web.1]:    from    
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:251:in `require'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:251:in `block in require'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:251:in `require'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:359:in `require_or_load'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:236:in `load_dependency'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:313:in `depend_on'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-
3.2.11/lib/active_support/dependencies.rb:225:in `require_dependency'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/engine.rb:438:in `each'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/engine.rb:436:in 
`eager_load!'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/engine.rb:438:in `block in 
eager_load!'
2013-11-28T03:39:50.220378+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/engine.rb:439:in `block (2 
levels) in eager_load!'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/application/finisher.rb:53:in 
`block in <module:Finisher>'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/initializable.rb:30:in 
`instance_exec'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `run'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/engine.rb:436:in `each'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `each'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/initializable.rb:54:in 
`run_initializers'
2013-11-28T03:39:50.220696+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'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/application.rb:136:in 
`initialize!'
2013-11-28T03:39:50.220696+00:00 app[web.1]:    from /app/config/environment.rb:5:in 
`<top (required)>'
2013-11-28T03:39:50.220696+00:00 app[web.1]:    from /app/config.ru:in `<main>'
2013-11-28T03:39:50.220696+00:00 app[web.1]:    from /app/config.ru:3:in `require'
2013-11-28T03:39:50.220557+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/initializable.rb:55:in `block   
in run_initializers'
2013-11-28T03:39:50.220696+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/railtie/configurable.rb:30:in 
`method_missing'
2013-11-28T03:39:50.220696+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'
2013-11-28T03:39:50.220696+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'
2013-11-28T03:39:50.220696+00:00 app[web.1]:    from /app/config.ru:in `new'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/commands/server.rb:70:in 
`start' 
2013-11-28T03:39:50.220696+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'
2013-11-28T03:39:50.221093+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'
2013-11-28T03:39:50.221093+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'
2013-11-28T03:39:50.220696+00:00 app[web.1]:    from /app/config.ru:3:in `block in 
<main>'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/commands/server.rb:46:in `app'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from 
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/commands.rb:50:in `tap'
2013-11-28T03:39:50.221093+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'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from  
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/commands.rb:55:in `block in 
<top (required)>'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from   
/app/vendor/bundle/ruby/2.0.0/gems/railties-3.2.11/lib/rails/commands.rb:50:in `<top 
(required)>'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from script/rails:6:in `require'
2013-11-28T03:39:50.221093+00:00 app[web.1]:    from script/rails:6:in `<main>'
2013-11-28T03:39:51.352167+00:00 heroku[web.1]: Process exited with status 1
2013-11-28T03:39:51.375056+00:00 heroku[web.1]: State changed from starting to crashed

我不明白为什么会出现此错误，因为我没有 /models/user.rb/。是的。我实际上做了一次并删除了它。

你能给我一些建议吗？

【问题讨论】：

您是否承诺删除它并推动该更改？

标签： ruby-on-rails ruby ruby-on-rails-3 heroku

【解决方案1】：

对于那些将来阅读本文的人：这是一个潜在的解决方案：

潜在原因是什么？

很可能，在您的代码的某个地方，您已经两次定义了同一个类。在这种特殊情况下，也许class User 两次 - 在两个不同的地方定义。在我的特殊情况下，我在测试代码库的两个不同位置有相同的类和相同的文件名。也许你的情况是一样的？运行一个快速的 grep 来检查可能是值得的。希望对您有所帮助。

【讨论】：

【解决方案2】：

我确信这个问题对你来说并不现实。但是对于将在这里寻找解决方案的人，我只想提一个可能的原因。在遵循 Michael Hartl 的“Rails Tutorial”时，我遇到了这样的错误。就我而言，这是我的疏忽——我将文件 example_user.rb （来自4.4.5 A user class 章）不是在应用程序的根目录中，而是在控制器文件夹中。在我解决了这个问题之后——Heroku 的问题就消失了。

【讨论】：

【解决方案3】：

看看

/app/app/models/user.rb

应用程序/应用程序？这是关闭的。调查您的项目来源，您确实有一个 user.rb 文件

【讨论】：

/app 是 Heroku 根目录，所以 /app/app 是你项目的 app 文件夹。
谢谢 ThelrishGuy 先生，我设法解决了这个问题。我只是忘记在 git 上暂存一些已删除的文件。所以，我不仅在本地删除了已删除的文件，而且在 git 上删除了文件。
感谢您的建议，七海猫先生。