Deploying Rakefiles?

My rakefile contains some tasks that are dev only. For example, test/
rails. Of course, test/rails is not present on the production server so
running rake breaks.

What are others doing? Do you have a dev and a production rakefile? Do
you have conditional requires? How about your tasks/ directory – how do
you keep that clear of any tasks that rely on things only present on
your dev computer?