Note to myself

After generating through yeoman, generally do
npm install and bower update before running any grunt tasks, otherwise it probably will come back with some error messages.

More details about this here: (this is for official backbone generator from Yeoman.io)
http://www.justinmccandless.com/blog/Getting+a+Yeoman+App+Working+on+a+New+Machine+after+Cloning
and here
https://github.com/gruntjs/grunt-contrib-compass/issues/194

Literally pulled hair out because of this stupid issue…