I want to use private pub gem in my rails application. I implement with railscast 316
After rails g private_pub:install
my private_pub.yml file:
development:
  server: "http://0.0.0.0:9292/faye"
  secret_token: "secret"
test:
  server: "http://0.0.0.0:9292/faye"
  secret_token: "secret"
production:
  server: "http://0.0.0.0/faye"
  secret_token: "98ec77eb7077c9899dc53f003abc4d6a0170512a57feab126ed5a32b114e3613"
  signature_expiration: 3600 # one hour
my private_pub.ru file
    # Run with: rackup private_pub.ru -s thin -E production
    require "bundler/setup"
    require "yaml"
    require "faye"
    require "private_pub"
    Faye::WebSocket.load_adapter('thin')
    PrivatePub.load_config(File.expand_path("../config/private_pub.yml", __FILE__), ENV["RAILS_ENV"] || "development")
    run PrivatePub.faye_app
Faye::Logging.log_level = :debug
Faye.logger = lambda { |m| puts m }
my index file
<h1>Chat</h1>
<ul id="chat">
  <%= render @mesajlar %>
</ul>
<%= form_for Mesaj.new, remote: true do |f| %>
    <%= f.text_field :icerik %>
    <%= f.submit "Send" %>
<% end %>
<%= subscribe_to "/mesajlar/new" %>
Controller file:
def create
params[:mesaj][:gonderen_id]= current_kullanici.id
@mesaj = Mesaj.create!(params[:mesaj])
PrivatePub.publish_to("/mesajlar/new", "alert('#{@mesaj.icerik}');")
end 
I add //= require private_pub to application.js file 
After the page was initialized I get the error below on firebug:
**PrivatePub is not defined**
at 
<script type="text/javascript">PrivatePub.sign({"server":"http://0.0.0.0:9292","timestamp":1363853952047,"channel":"/mesajlar/new","signature":"7bf74474796412b524b6c6c8849c50cb245ce92d"});</script>
</div> 
And no output in Rails log and RAILS_ENV=production bundle exec rackup private_pub.ru -s thin -E production commands log
I searched and no found a solution.
Where is the problem?