

class FeatureLibError(Exception):
    def __init__(self, message, location):
        Exception.__init__(self, message)
        self.location = location

    def __str__(self):
        message = Exception.__str__(self)
        if self.location:
            path, line, column = self.location
            return "%s:%d:%d: %s" % (path, line, column, message)
        else:
            return message


class IncludedFeaNotFound(FeatureLibError):
    pass
