def METHOD_NAME(self):
	"""
	see WAF issue 285 and also and also http://trac.macports.org/ticket/17059
	"""
	if self.env.MACOSX_DEPLOYMENT_TARGET:
		os.environ['MACOSX_DEPLOYMENT_TARGET'] = self.env.MACOSX_DEPLOYMENT_TARGET
	elif 'MACOSX_DEPLOYMENT_TARGET' not in os.environ:
		if Utils.unversioned_sys_platform() == 'darwin':
			os.environ['MACOSX_DEPLOYMENT_TARGET'] = '.'.join(platform.mac_ver()[0].split('.')[:2])