deprecation warning, changelog entry

actionpack/CHANGELOG.md

 ## Rails 3.2.0 (unreleased) ##
 
+*   Refactor ActionDispatch::ShowExceptions. Controller is responsible for choice to show exceptions. *Sergey Nartimov*
+
+    It's possible to override +show_detailed_exceptions?+ in controllers to specify which requests should provide debugging information on errors.
+
 *   Responders now return 204 No Content for API requests without a response body (as in the new scaffold) *José Valim*
 
 *   Added ActionDispatch::RequestId middleware that'll make a unique X-Request-Id header available to the response and enables the ActionDispatch::Request#uuid method. This makes it easy to trace requests from end-to-end in the stack and to identify individual requests in mixed logs like Syslog *DHH*

actionpack/lib/action_dispatch/middleware/show_exceptions.rb

@@ -2,6 +2,7 @@
 require 'action_controller/metal/exceptions'
 require 'active_support/notifications'
 require 'action_dispatch/http/request'
+require 'active_support/deprecation'
 
 module ActionDispatch
   # This middleware rescues any exception returned by the application and renders
@@ -38,7 +39,8 @@ class ShowExceptions
        "application's log file and/or the web server's log file to find out what " <<
        "went wrong.</body></html>"]]
 
-    def initialize(app)
+    def initialize(app, consider_all_requests_local = nil)
+      ActiveSupport::Deprecation.warn "Passing consider_all_requests_local option to ActionDispatch::ShowExceptions middleware no longer works" unless consider_all_requests_local.nil?
       @app = app
     end