`method_missing': undefined method `devise' for User (call 'User.connection' to establish a connection)

Question

I am new to Ruby on Rails and am trying to make my first application. I am having issues though anytime I run any rails generate command. I get the following error

MyUsers-MacBook-Pro:MyApp MyUser$ rails generate devise:install Warning: Running `gem pristine --all` to regenerate your installed gemspecs (and deleting then reinstalling your bundle if you use bundle --path) will improve the startup performance of Spring. /Users/MyUser/.gem/ruby/2.0.0/gems/activerecord-4.1.2.rc1/lib/active_record/dynamic_matchers.rb:26:in `method_missing': undefined method `devise' for User (call 'User.connection' to establish a connection):Class (NoMethodError)     from /Users/MyUser/.Trash/MyApp/app/models/user.rb:4:in `<class:User>'     from /Users/MyUser/.Trash/MyApp/app/models/user.rb:1:in `<top (required)>'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:443:in `load'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:443:in `block in load_file'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:633:in `new_constants_in'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:442:in `load_file'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:342:in `require_or_load'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:480:in `load_missing_constant'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:180:in `const_missing'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/inflector/methods.rb:238:in `const_get'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/inflector/methods.rb:238:in `block in constantize'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/inflector/methods.rb:236:in `each'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/inflector/methods.rb:236:in `inject'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/inflector/methods.rb:236:in `constantize'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:552:in `get'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:583:in `constantize'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise.rb:297:in `get'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/mapping.rb:77:in `to'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/mapping.rb:72:in `modules'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/mapping.rb:89:in `routes'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/mapping.rb:156:in `default_used_route'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/mapping.rb:66:in `initialize'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise.rb:331:in `new'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise.rb:331:in `add_mapping'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/rails/routes.rb:221:in `block in devise_for'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/rails/routes.rb:220:in `each'     from /Library/Ruby/Gems/2.0.0/gems/devise-3.2.4/lib/devise/rails/routes.rb:220:in `devise_for'     from /Users/MyUser/.Trash/MyApp/config/routes.rb:2:in `block in <top (required)>'     from /Users/MyUser/.gem/ruby/2.0.0/gems/actionpack-4.1.2.rc1/lib/action_dispatch/routing/route_set.rb:337:in `instance_exec'     from /Users/MyUser/.gem/ruby/2.0.0/gems/actionpack-4.1.2.rc1/lib/action_dispatch/routing/route_set.rb:337:in `eval_block'     from /Users/MyUser/.gem/ruby/2.0.0/gems/actionpack-4.1.2.rc1/lib/action_dispatch/routing/route_set.rb:315:in `draw'     from /Users/MyUser/.Trash/MyApp/config/routes.rb:1:in `<top (required)>'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:241:in `load'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:241:in `block in load'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:232:in `load_dependency'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:241:in `load'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:40:in `each'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:40:in `load_paths'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:16:in `reload!'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:26:in `block in updater'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/file_update_checker.rb:75:in `call'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/file_update_checker.rb:75:in `execute'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:27:in `updater'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/routes_reloader.rb:7:in `execute_if_updated'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application/finisher.rb:71:in `block in <module:Finisher>'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/initializable.rb:30:in `instance_exec'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/initializable.rb:30:in `run'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/initializable.rb:55:in `block in run_initializers'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:180:in `each'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'     from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/initializable.rb:54:in `run_initializers'     from /Users/MyUser/.gem/ruby/2.0.0/gems/railties-4.1.2.rc1/lib/rails/application.rb:300:in `initialize!'     from /Users/MyUser/.Trash/MyApp/config/environment.rb:5:in `<top (required)>'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:247:in `require'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:247:in `block in require'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:232:in `load_dependency'     from /Users/MyUser/.gem/ruby/2.0.0/gems/activesupport-4.1.2.rc1/lib/active_support/dependencies.rb:247:in `require'     from /Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/application.rb:92:in `preload'     from /Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/application.rb:140:in `serve'     from /Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/application.rb:128:in `block in run'     from /Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/application.rb:122:in `loop'     from /Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/application.rb:122:in `run'     from /Library/Ruby/Gems/2.0.0/gems/spring-1.1.3/lib/spring/application/boot.rb:18:in `<top (required)>'     from /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'     from /Library/Ruby/Site/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'     from -e:1:in `<main>' 

Even if I don't add the gem 'devise' into my Gemfile I still get that error. I even created a new application and get that error.

I have even tried the answers at undefined method 'devise' for User

Any idea how I can get rid of this error?

EDIT I currently do not have any models

Answer 1

This happens because you missed the command:

rails generate devise:install 

You need just comment all devise lines temporally (in routes.rb / user.rb) to not get raise.
And run command again.

Answer 2

This is the appropriate Order.

gem 'devise' Run the bundle command to install it. rails generate devise:install rails generate devise MODEL 

Here Model was created before the "rails generate devise:install".So you have to go back an comment everything that model created :

class User < ActiveRecord::Base # Include default devise modules. Others available are: # :confirmable, :lockable, :timeoutable and :omniauthable #devise :database_authenticatable, :registerable, #:recoverable, :rememberable, :trackable, :validatable end 

and also this

Rails.application.routes.draw do #devise_for :users end 

Now,Run "rails generate devise:install" and after that uncomment the above .