Doesn't seem like the css class prefix is being set when coming from a build url

example:

http://modernizr.com/download?-cssanimations-csstransitions-touchevents-domprefixes-mq-prefixed-prefixes-setclasses-testallprops-testprop-teststyles-dontmin-cssclassprefix:modernizr-

What is expected::

modernizr build page with all customizations checked and input areas filled out

What happens::
all customizations including add class are checked to be used; however, the field for class prefix isn't populated with the passed in url attribute. In this example I would expect to see -

(✓) Add CSS classes
...with prefix [ modernizr- ]