How to disable 3D acceleration on the Mac Book Air?
One way of disabling your graphics is safe mode. I don't know if your xcode debug tool will run in safe mode but unless you know otherwise, I think it's worth a shot. good luck
OS X: What is Safe Boot, Safe Mode?
Safe Mode in Mac OS X v10.5 or later also disables Quartz Extreme (hardware accelerated graphics). Applications that depend on Quartz Extreme do not open in Safe Mode, and the Mac OS X menu bar will appear solid even if "Translucent Menu Bar" is enabled in Desktop & Screen Saver preferences.