Что означает эта ошибка при разработке?

Question

Когда я пытаюсь запустить мой рельсы сервер я получаю следующее сообщение об ошибке (Важное примечание: я просто вытащил свой код из Github в Nitrous.Io, и начал работать над приложением):

/home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:226:in `const_get': uninitialized constant User (NameEr 
ror)                                         from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:226:in `block in constantize'    
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `each'        
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `inject'       
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `constantize'      
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise.rb:285:in `get'                
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/mapping.rb:77:in `to'               
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/mapping.rb:72:in `modules'              
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/mapping.rb:89:in `routes'              
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/mapping.rb:156:in `default_used_route'           
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/mapping.rb:66:in `initialize'             
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise.rb:319:in `new'                
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise.rb:319:in `add_mapping'              
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/rails/routes.rb:210:in `block in devise_for'         
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/rails/routes.rb:209:in `each'             
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/devise-3.1.1/lib/devise/rails/routes.rb:209:in `devise_for'           
     from /home/action/pinteresting/config/routes.rb:4:in `block in <top (required)>'                  
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `instance_exec'      
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `eval_block'       
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:294:in `draw'        
     from /home/action/pinteresting/config/routes.rb:1:in `<top (required)>' 
from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'     
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `each'         
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `load_paths'        
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:16:in `reload!'        
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:26:in `block in updater'      
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `call'        
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `execute'       
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:27:in `updater'        
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:6:in `execute_if_updated'      
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/finisher.rb:69:in `block in <module:Finisher>'     
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'          
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'             
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'       
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'              
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'     
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'         
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'        
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each'                  
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'          
     from /home/action/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'  
from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'          
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'           
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'        
     from /home/action/pinteresting/config/environment.rb:5:in `<top (required)>'                   
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application.rb:189:in `require_environment!'         
     from /home/action/.rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:45:in `<top (required)>'           
     from bin/rails:4:in `require'                               
     from bin/rails:4:in `<main>' 

Answer 1

Looks так как ваша база данных еще не создана.

Наиболее вероятным решением было бы запустить rake db:migrate, если вы используете sqlite, хотя если вы используете Postgres или Mysql on Nitrous, вам сначала нужно их установить. Есть руководство к тому, что доступно здесь http://help.nitrous.io/categories/databases/