Freezing to latest edge rails will break your app

But only for a brief second! The culprit? The switching of the default Rails session management method over to a cookie based management system. Right after I froze to edge, I started my app up and immediately tried to access it. Blam, it blew up in my face. Right there in the server console it was telling me I needed to stick

session :secret => "secret phrase here"

in my Application.rb. Doing that made everything better. You can read and dig into all what Jeremy added in this change set here.