def is_builder_newer(old_component, new_component):
    """
    Return True if the given builder has been modified with respect to its
    state when the given component_meta was created.

    :param old_component: a dict of metadata describing a component ring
    :param new_component: a dict of metadata describing a component ring
    :return: True if the builder has been modified, False otherwise.
    :raises ValueError: if the version of the new_component is older than the
                        version of the existing component.
    """
    if new_component['version'] < old_component['version']:
        raise ValueError('Older builder version: %s < %s' % (new_component[
            'version'], old_component['version']))
    return old_component['version'] < new_component['version']
