Comment 3 for bug 1253858

It seems there was an error communicating with your mirror of the Ubuntu archive:
2013-11-21 20:32:52,077 ERROR IOError/SystemError in cache.update(): 'W:GPG error: http://deb.opera.com stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E585066A30C18A2B, W:GPG error: http://deb.opera.com stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E585066A30C18A2B, W:Failed to fetch http://ht.archive.ubuntu.com/ubuntu/dists/saucy/Release.gpg Something wicked happened resolving 'ht.archive.ubuntu.com:http' (-11 - System error)
, W:Failed to fetch http://security.ubuntu.com/ubuntu/dists/saucy-security/Release.gpg Something wicked happened resolving 'security.ubuntu.com:http' (-11 - System error)
, W:Failed to fetch http://archive.canonical.com/ubuntu/dists/saucy/Release.gpg Something wicked happened resolving 'archive.canonical.com:http' (-11 - System error)
, E:Some index files failed to download. They have been ignored, or old ones used instead.'. Retrying (currentRetry: 0)

Please try the upgrade again after verifying your network connection or with a different mirror.