Nathan Weizenbaum got fed up debugging Sass, and scratched his itch withFireSass, a Firebug extension for Sass (the “Syntactically Awesome Stylesheets” DSL that makes CSS more fun).
WIth the extension you will see the filename and line number of the .sass file rather than the generated CSS file…. Much nicer!
http://ajaxian.com/archives/firesass