The /usr/lib/update-notifier/apt-check script returns its output
to STDERR but a recent change to the script redirects STDERR to
/dev/null. This will cause the array to always be empty.
Combined with that problem, while we were checking for the result
being nil, we never checked for an invalid array. As a result,
the apt_has_updates was always true and the apt_updates and
apt_security_updates facts were trying to read from an empty array
and failing.
Making use of the apt-check command from the 'update-notifier-common'
package (if available) display the number of available updates, number of
security updates as well as the update package names.
