sindresorhus/grunt-sass — pull request #54 by swist (2014-01-03 16:25:34+00:00)
Title: Basic support for sourcemaps

Salient points:
- sourcemaps currently can only live as a sibling of the .css
- Haven't tested if specifying the path for the sourcemap works, just had to pass something to node-sass for it to compile it.
- Requires you to build node-sass from source

Perhaps merge once node-sass with sourcemap support shows up on npm?