On Wed, 17 Feb 2016 11:04:04 +0100
Didier Kryn <kryn@???> wrote:

>      I think 'dpkg-reconfigure <package-name>' should work.

You got me wrong ;) I have here a script that got stuck on the latest
glibc/locales update (apt-get upgrade -y -q). The log shows, that it
ran into interactive debconf. After downgrading to the previous
"locales" version, the script smoothly does its job, no way to
reproduce the problem, whereas /var/cache/debconf/config.dat does not
contain any version information.

Assumptions so far: To trigger interactive debconf on a package
upgrade...

a) as local admin, I'd have to mess with /var/cache/debconf/config.dat
or reconfigure debconf to present lower-priority questions.

b) as a package maintainer, I could modify the package's
debconf-igurable items or their syntax.

Conclusion: To make an unattended upgrade script more robust, I have to
export "DEBIAN_FRONTEND=noninteractive" before running the upgrade. But
thus I risk ending up with un-debconf-igured packages on my system (see
"assumptions" above).

Follow-up (meta) question: For safe unattended upgrades, wouldn't it
make sense to force packages that come with modified debconf rules into
the "dist-upgrade" workflow?


Florian