ruby script console error in edge version


I try to play with edge version of rails. Maybe someday I could be
rails contributor. :slight_smile:
Ok, based on rails recipe books by martin, I do this:
$ rails example_rails_hack (I have rails 1.2 version)
$ cd example_rails_hack/vendor
$ svn co rails

The fast way to play with this edge version is through console. So....
$ cd ..
$ ruby script/console

But I got this error:
Loading development environment.
dependencies.rb:477:in `const_missing':NameError: uninitialized
constant ActionController::Base::DEPRECATED_INSTANCE_VARIABLES
application.rb:6:NoMethodError: undefined method `session' for

Any idea how to fix this?

Thank you.