Always define controller action methods in Rails 3

This morning was spent puzzling over a strange hard-to-reproduce Cucumber test failure in a project I have been upgrading from Rails 2.3.x to 3.0.3. It was only occurring after certain steps had been taken in previous Scenarios, and not when the failing Scenario was run on its own.

The solution was to explicitly define the controller action’s method in the controller. So the question to the world is: what changed, ActionController or something in the Cucumber chain?