Devise omniauth integration problem

I have watched railscast http://railscasts.com/episodes/236-omniauth-part-2

And tried to implement the code, everything worked well in development environment. when I executed using rails s -e production, I get the error below

omniauth_callbacks_controller.rb:1: uninitialized constant Devise::OmniauthCallbacksController (NameError)

The code snippet that caused error is here

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController

My Gemfile

gem 'aws-s3'
gem 'paperclip'
gem 'rails', '3.0.0'
gem 'pg'
gem 'gravatar_image_tag', '0.1.0'
gem 'will_paginate', '3.0.pre2'
gem 'devise'
gem 'omniauth'
gem 'nifty-generators'

My Gemfile.lock file (just related ones)

    devise (1.1.5)
      bcrypt-ruby (~> 2.1.2)
      warden (~> 1.0.2)

    nokogiri (1.4.4)
    oa-basic (0.1.6)
      multi_json (~> 0.0.2)
      nokogiri (~> 1.4.2)
      oa-core (= 0.1.6)
      rest-client (~> 1.6.0)
    oa-core (0.1.6)
      rack (~> 1.1)
    oa-enterprise 开发者_运维问答(0.1.6)
      net-ldap (~> 0.1.1)
      nokogiri (~> 1.4.2)
      oa-core (= 0.1.6)
      pyu-ruby-sasl (~> 0.0.3.1)
      rubyntlm (~> 0.1.1)
    oa-oauth (0.1.6)
      multi_json (~> 0.0.2)
      nokogiri (~> 1.4.2)
      oa-core (= 0.1.6)
      oauth (~> 0.4.0)
      oauth2 (~> 0.1.0)
    oa-openid (0.1.6)
      oa-core (= 0.1.6)
      rack-openid (~> 1.2.0)
      ruby-openid-apps-discovery
    oauth (0.4.4)
    oauth2 (0.1.0)
      faraday (~> 0.5.0)
      multi_json (~> 0.0.4)
    omniauth (0.1.6)
      oa-basic (= 0.1.6)
      oa-core (= 0.1.6)
      oa-enterprise (= 0.1.6)
      oa-oauth (= 0.1.6)
      oa-openid (= 0.1.6)

My development.rb file

SampleApp::Application.configure do
  config.cache_classes = false
  config.whiny_nils = true
  config.consider_all_requests_local       = true
  config.action_view.debug_rjs             = true
  config.action_controller.perform_caching = false
  config.action_mailer.raise_delivery_errors = false
  config.active_support.deprecation = :log
  config.action_dispatch.best_standards_support = :builtin
  config.action_mailer.default_url_options = { :host => 'localhost:3000' }
end

My production.rb file

SampleApp::Application.configure do
  config.cache_classes = true
  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true
  config.action_dispatch.x_sendfile_header = "X-Sendfile"
  config.serve_static_assets = false
  config.i18n.fallbacks = true
  config.active_support.deprecation = :notify
end

Can anyone help?

In devise 1.2, it's supports integration with OmniAuth directly.

Check devise wiki for OmniAuth

What's your Gemfile look like? Did you stick the gem 'omniauth' statement in a :development group by any chance?