Tracking Supplies

Yeah, double-check your paths. They need to be absolute paths to the appropriate folders on your server. But did the build script work? Did it generate the class files and maps? If so, then your paths in your build.config.php file must be correct, so that means you must have the path of your modx install correct.

Could you post your settings for doodles.core_path (or whatever you're calling your extra) and doodles.assets_url, the contents of your build.config.php file, and also the full code of your snippet?

I bet there's just a typo somewhere, that's usually what this sort of problem is.