visionmedia/express — pull request #1625 by ForbesLindesay (2013-05-15 01:18:58+00:00)
Title: Throw a meaningful error when there is no default engine

See https://github.com/visionmedia/jade/issues/1023 for an example of the current lack of helpful error messages biting people (@lbj96347).

I've run into this myself before as well at some point.