安装rails_admin，一切都停止工作
所以我想创建一个应用程序，人们可以在这里查看艺术。 问题是，只有管理员才能创建，编辑和删除数据。 所以我想添加一个管理界面。 我选择了rails_admin gem。
我已经按照git文档中的说法安装了所有内容，但是当我安装它时，一切都停止了。 我无法生成脚手架，模型或控制器，我无法启动我的服务器。 每当我尝试一些东西时它就会给我这个信息。
/Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.3/lib/active_support/inflector/methods.rb:229:in `block in constantize': uninitialized constant Admin (NameError) from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.3/lib/active_support/inflector/methods.rb:228:in `each' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.3/lib/active_support/inflector/methods.rb:228:in `constantize' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise.rb:256:in `get' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/mapping.rb:77:in `to' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/mapping.rb:72:in `modules' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/mapping.rb:89:in `routes' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/mapping.rb:156:in `default_used_route' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/mapping.rb:66:in `initialize' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise.rb:290:in `new' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise.rb:290:in `add_mapping' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/rails/routes.rb:208:in `block in devise_for' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/rails/routes.rb:207:in `each' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/devise-2.1.2/lib/devise/rails/routes.rb:207:in `devise_for' from /Users/Max/Desktop/walls/config/routes.rb:18:in `block in ' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:282:in `instance_exec' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:282:in `eval_block' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/actionpack-3.2.3/lib/action_dispatch/routing/route_set.rb:260:in `draw' from /Users/Max/Desktop/walls/config/routes.rb:1:in `' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:40:in `block in load_paths' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:40:in `each' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:40:in `load_paths' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:16:in `reload!' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:26:in `block in updater' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.3/lib/active_support/file_update_checker.rb:78:in `call' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.3/lib/active_support/file_update_checker.rb:78:in `execute' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:27:in `updater' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/routes_reloader.rb:7:in `execute_if_updated' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application/finisher.rb:66:in `block in ' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `instance_exec' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `run' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/initializable.rb:55:in `block in run_initializers' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `each' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `run_initializers' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/application.rb:136:in `initialize!' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/railtie/configurable.rb:30:in `method_missing' from /Users/Max/Desktop/walls/config/environment.rb:5:in `' from /Users/Max/Desktop/walls/config.ru:4:in `block in ' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize' from /Users/Max/Desktop/walls/config.ru:1:in `new' from /Users/Max/Desktop/walls/config.ru:1:in `' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:200:in `app' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands/server.rb:46:in `app' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/rack-1.4.1/lib/rack/server.rb:252:in `start' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands/server.rb:70:in `start' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands.rb:55:in `block in ' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands.rb:50:in `tap' from /Users/Max/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands.rb:50:in `' from script/rails:6:in `require' from script/rails:6:in `' 在安装rails_admin之前，我已经完成了所有数据的设置，所以如果我不得不重新开始，那将是非常糟糕的。
如果有人需要更多信息，我很乐意给它，但我不知道现在要发布什么。
看看你的routes.rb，我必须有一些像devise_for这样的代码：admin_users，ActiveAdmin :: Devise.config
删除它或删除它。 您已经删除了管理员，但可能没有修改路由。
要再次返回工作项目状态，请从Gemfile中删除gem“rails_admin”声明，从config / initializers目录中删除rails_admin.rb文件，然后从config / routes.rb中删除rails_admin生成的路由：
devise_for :admins mount RailsAdmin::Engine => '/rails_admin', :as => 'rails_admin'
这就是导致Devise寻找Admin模型的原因。 删除它，以及删除gem和初始化程序文件应该从项目中删除整个事情。