(Unrelated: to be "purge" safe, /etc/cron.daily/update-notifier-common should test for /usr/lib/update-notifier/package-data-downloader before executing it.)
(Unrelated: to be "purge" safe, /etc/cron. daily/update- notifier- common should test for /usr/lib/ update- notifier/ package- data-downloader before executing it.)