Find out why v1_controller tests are failing.

It's failing with a PHP error on the Jenkins server:
Unexpected PHP error [array_keys() expects parameter 1 to be array, null
given] severity [E_WARNING] in
[/var/lib/jenkins/jobs/iPeer_dev/workspace/cake/libs/set.php line 1100]

But I'm unable to duplicate it on my local machine. So trying out a few
guesses as to what's causing it.