def METHOD_NAME(self):
	"""
	Expands LOCALEDIR from DATAROOTDIR/locale if possible, or falls back to PREFIX/share/locale
	"""
	# use the tool gnu_dirs to provide options to define this
	if not self.env.LOCALEDIR:
		if self.env.DATAROOTDIR:
			self.env.LOCALEDIR = os.path.join(self.env.DATAROOTDIR, 'locale')
		else:
			self.env.LOCALEDIR = os.path.join(self.env.PREFIX, 'share', 'locale')