Devise is not creating a User.rb model when I run the model generator

[WARNING] You provided devise_for :users but there is no model User defined in your application

I've done some googling and it seems this is something do with setting up the ORM configuration for devise.rb in config/initializers which I had done:

require 'devise/orm/开发者_JS百科mongo_mapper'

Is there something I am missing? What do I need to do to get the Devise generators to work with mongomapper?

Don't forget to set

Devise.setup do |config|
  config.orm = :mongo_mapper
  ...
end

in your initialiser as well.