Bug. It will Always remove lock.

[SawyerLan]

    if should_update and created_file(lock):
        try:
            d = urllib2.urlopen(endpoint).read()
            with open(cache, 'w') as f: f.write(d)
        except Exception as e:
            print e
        if os.path.exists(lock):
            os.remove(lock)

This will always remove lock file.