config.action_controller.include_all_helpers = false NEW

after using it
config.action_controller.include_all_helpers = false

when trying to run any ApplicationController method like (testing)

class ApplicationController < ActionController::Base
  def checking

running in console
=> Debugger enabled
Loading development environment (Rails 3.1.0.rc5)
ruby-1.9.2-p290 :001 > checking
NameError: undefined local variable or method `checking' for

what's new about it ... ? none of the ApplicationController can be
run ...

If I understand correctly then it appears you are trying to call an
ApplicationController method from the console. ApplicationController
methods can only be called from the context of a controller (if that
is the right way of putting it). Otherwise it does not have a
controller to call the method on.

Also I do not understand the significance of include_all_helpers in this.