code: def _getEngineRoot(self):
  		
  		override = ConfigurationManager.getConfigKey('rootDirOverride')
  		if override != None:
  			Utility.printStderr('Using user-specified engine root: ' + override)
  			return override
  		else:
  			return self._detectEngineRoot()
docs: Retrieves the user-specified engine root directory override (if set), or else performs auto-detection