gruntjs/grunt-contrib-compass — pull request #111 by TudorCampean (2013-12-01 18:47:06+00:00)
Title: Undefine property error on child if compass not installed.

It happened on using concurrent task on yeoman
On win7 if you didn't have compass installed it failed with a undefined property error .
With this shows a proper message that reminds you to check if you have it installed .