The issue occurred for me when the latest set of updates were applied. Just trying to remove avahi-dnsconfd give an error about the pre-removal script failing. Here is the output from 'apt remove avahi-dnsconfd'
# apt remove avahi-dnsconfd Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED avahi-dnsconfd 0 to upgrade, 0 to newly install, 1 to remove and 0 not to upgrade. After this operation, 92.2 kB disk space will be freed. Do you want to continue? [Y/n] (Reading database ... 602708 files and directories currently installed.) Removing avahi-dnsconfd (0.6.32-1ubuntu1) ... Job for avahi-daemon.socket canceled. dpkg: error processing package avahi-dnsconfd (--remove): subprocess installed pre-removal script returned error exit status 1 Errors were encountered while processing: avahi-dnsconfd E: Sub-process /usr/bin/dpkg returned an error code (1) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to avahi in Ubuntu. https://bugs.launchpad.net/bugs/1761682 Title: package avahi-dnsconfd 0.6.32-1ubuntu1 failed to install/upgrade: sub- process pre-removal script returned error-code 1 Status in avahi package in Ubuntu: Confirmed Bug description: Occurred during 'sudo apt full-upgrade'. ProblemType: Package DistroRelease: Ubuntu 17.10 Package: avahi-dnsconfd 0.6.32-1ubuntu1 ProcVersionSignature: Ubuntu 4.13.0-37.42-generic 4.13.13 Uname: Linux 4.13.0-37-generic x86_64 ApportVersion: 2.20.7-0ubuntu3.7 Architecture: amd64 Date: Fri Apr 6 09:22:10 2018 ErrorMessage: Unterprozess neues pre-removal-Skript gab den Fehlerwert 1 zurück InstallationDate: Installed on 2015-06-02 (1038 days ago) InstallationMedia: Ubuntu-GNOME 15.04 "Vivid Vervet" - Release amd64 (20150422) Python3Details: /usr/bin/python3.6, Python 3.6.3, python3-minimal, 3.6.3-0ubuntu2 PythonDetails: /usr/bin/python2.7, Python 2.7.14, python-minimal, 2.7.14-2ubuntu1 RelatedPackageVersions: dpkg 1.18.24ubuntu1 apt 1.5.1 SourcePackage: avahi Title: package avahi-dnsconfd 0.6.32-1ubuntu1 failed to install/upgrade: Unterprozess neues pre-removal-Skript gab den Fehlerwert 1 zurück UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1761682/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : email@example.com Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp