Ah, I think I know what's going on. While trying to reproduce your problem, I grabbed a copy of Tera-WURFL from GitHub and set it up - I had the same problem as you (the problem is technically the xdebug extension's max recursion depth). Then I was stumped until I realized that I was downloading the tagged 2.1.4 release and not the current source.
Please make sure you download the current source, and not the 2.1.4 release!: