The bug was from https://github.com/rajivnavada/bootstrap/commit/49d565a6da38..., which used /bin/cat inappropriately. Parsing x+y is not equivalent to parsing x fully and then y, so javascript-aware tools are required for that sort of packaging.

This problem is very prevalent when concatenating JavaScript. The best defense is to prepend a semicolon before anonymous function closures.

For example, see Paul Irish's geo-location shim https://gist.github.com/366184