see also https://bugs.launchpad.net/ubuntu/+bug/1581341 and https://bugs.launchpad.net/ubuntu/+bug/1499516 and https://bugs.launchpad.net/ubuntu/+bug/1581331
see also https:/ /bugs.launchpad .net/ubuntu/ +bug/1581341 and https:/ /bugs.launchpad .net/ubuntu/ +bug/1499516 and https:/ /bugs.launchpad .net/ubuntu/ +bug/1581331