A momentous discovery (for me, anyway)
You can run Hammer for Mac and CodeKit on the same project at the same time!
Basically, I was getting frustrated that I couldn't use sass source maps in Chrome for debugging with Hammer for Mac. I'd bought CodeKit (and updated to the latest version) a while back but I'd never really used it because I like the HTML includes in Hammer for Mac so much* and CodeKit was always an app I thought I'd get around to grasping when I had some free time (yeah, I know).
Anyway, I was working on a project and finally got sick and tired of playing hunt-the-attribute when debugging the CSS/SCSS files. I thought about putting a watch on my scss files using the command line, but on a whim I opened up CodeKit and imported my project into it.
I soon realised that this might cause some problems if I used it to compile the whole project, but seeing as I only needed it to create a sass source map for me, I took a punt on using it to compile the top level sass file (style.scss)**.
It worked! I now have sass debugging goodness while keeping my original workflow intact. Win all round!
* I know CodeKit can use the kit language to do much the same thing, but I didn't want yet something else to compile every time I made a change
** Someone's bound to tell me that this isn't a good idea, but what the hell. I love fixing total trainwrecks :)