def normalizeURL(url):
    """Normalize a URL, converting normalization failures to
    DiscoveryFailure"""
    try:
        normalized = urinorm.urinorm(url)
    except ValueError, why:
        raise DiscoveryFailure('Normalizing identifier: %s' % (why[0],), None)
    else:
        return urlparse.urldefrag(normalized)[0]