Rails : Error omniauth + rack

Error following below
[FATAL]
NoMethodError (undefined method `include?' for nil:NilClass):
  omniauth (1.1.0) lib/omniauth/builder.rb:47:in `call'
  actionpack (3.2.2) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
  rack (1.4.0) lib/rack/etag.rb:23:in `call'
  ....

Solution
  fixed  in gem with rack, '~> 1.4.0'