Mcrypt is installed, but error implies it's not.

Codeigniter 2.2 displays error, “The Encrypt library requires the Mcrypt extension.”
I’m running PHP 5.6.2 (via MAMP) on Yosemite 10.10.1.

Phpinfo says mcrypt is enabled. The php log shows no error. Apache log shows no error. This issue occurs only in my local environment. My dev and production environments don’t throw the error (Ubuntu 11.10)

I know this has been a common snag with the CI 2.2 upgrade, but mcrypt problems appear resolved when PHP is upgraded, or mcrypt is installed. What am I missing?