这篇文章上次修改于 1947 天前，可能其部分内容已经发生变化，如有疑问可询问作者。

参考
rails g devise:install

rails g devise install != rails g devise:install

I ran into this problem as well. Executing rails generate devise install (sic!) there was nothing that seemed not to have worked. The terminal output was:

$ rails g devise install
Running via Spring preloader in process 5422

  invoke  active_record
  create    db/migrate/20180306165306_devise_create_installs.rb
  create    app/models/install.rb
  insert    app/models/install.rb
   route  devise_for :installs

But I missed the semicolon. Reverting these changes and then executing rails generate devise:install (note the : between devise and install), everything worked out perfectly. Also you get a much more extensive output:

$ rails g devise:install
Running via Spring preloader in process 5218

  create  config/initializers/devise.rb
  create  config/locales/devise.en.yml

===============================================================================

Some setup you must do manually if you haven't yet:

1. Ensure you have defined default url options in your environments files. Here
   is an example of default_url_options appropriate for a development environment
   in config/environments/development.rb:

     config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

   In production, :host should be set to the actual host of your application.

2. Ensure you have defined root_url to *something* in your config/routes.rb.
   For example:

     root to: "home#index"

3. Ensure you have flash messages in app/views/layouts/application.html.erb.
   For example:

     <p class="notice"><%= notice %></p>
     <p class="alert"><%= alert %></p>

4. You can copy Devise views (for customization) to your app by running:

     rails g devise:views

===============================================================================