How can I disable sass warnings via config.rb?

#1

SASS 3.4.11 introduced deprecation warnings which seem to clash with the current version of compass, susy and possibly autoprefixer:

DEPRECATION WARNING: Passing null, a non-string value, to unquote()   
will be an error in future versions of Sass.

---followed by a stack dump---

These are not actionable and are just polluting the console output

Is there a way to disable them in config.rb?

#2

Switched to Sass 3.4.9 in my gemfile for the time being. Having the option to hide the warnings would be nicer.