Thank you for reporting a bug and helping to make Ubuntu better. Based on https://launchpadlibrarian.net/473334677/DpkgTerminalLog.txt:
Preparing to unpack .../archives/ufw_0.36-6_all.deb ... Unpacking ufw (0.36-6) over (0.36-5) ... Setting up ufw (0.36-6) ... Configuration file '/etc/default/ufw' ==> Modified (by you or by a script) since installation. ==> Package distributor has shipped an updated version. What would you like to do about it ? Your options are: Y or I : install the package maintainer's version N or O : keep your currently-installed version D : show the differences between the versions Z : start a shell to examine the situation The default action is to keep your current version. *** ufw (Y/I/N/O/D/Z) [default=N] ? dpkg: error processing package ufw (--configure): end of file on stdin at conffile prompt Looking at https://launchpadlibrarian.net/473334680/modified.conffile..etc.default.ufw.txt I can see that the file (/etc/default/ufw) is missing the trailing newline from 0.36-5 (this file is not manipulated by the ufw command). I can't say why the file on your system was missing the trailing newline, but since it was, unattended-upgrades (seen in https://launchpadlibrarian.net/473334676/DpkgHistoryLog.txt) wasn't in a position to answer the conffile question. This is not a bug in ufw. To remedy the situation, you should be able to perform: sudo apt-get -f install. I also see that the system is running the current development release of Ubuntu. Unlike stable releases of Ubuntu, it is sometimes easier to disable unattended-upgrades when using the development release and instead run apt manually. If you disable it, feel free to re-enable it once Ubuntu 20.04 is released. Thanks again! ** Changed in: ufw (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ufw in Ubuntu. https://bugs.launchpad.net/bugs/1871261 Title: package ufw 0.36-6 failed to install/upgrade: end of file on stdin at conffile prompt Status in ufw package in Ubuntu: Invalid Bug description: No action on my part resulted in a report problem dialog. I have never modified the ufw configuration through the life of this install, which has come from 18.04 thru 19.04 and 19.10 to arrive at 20.04. Guessing someone made a typo in packaging. ProblemType: Package DistroRelease: Ubuntu 20.04 Package: ufw 0.36-6 ProcVersionSignature: Ubuntu 5.4.0-21.25-generic 5.4.27 Uname: Linux 5.4.0-21-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu24 AptOrdering: ufw:amd64: Install NULL: ConfigurePending Architecture: amd64 Date: Tue Apr 7 06:45:08 2020 ErrorMessage: end of file on stdin at conffile prompt InstallationDate: Installed on 2017-04-14 (1088 days ago) InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412) PackageArchitecture: all Python3Details: /usr/bin/python3.8, Python 3.8.2, python3-minimal, 3.8.2-0ubuntu2 PythonDetails: /usr/bin/python2.7, Python 2.7.17, python-is-python2, 2.7.17-3 RelatedPackageVersions: dpkg 1.19.7ubuntu3 apt 2.0.1 SourcePackage: ufw Title: package ufw 0.36-6 failed to install/upgrade: end of file on stdin at conffile prompt UpgradeStatus: Upgraded to focal on 2020-04-06 (0 days ago) mtime.conffile..etc.default.ufw: 2019-07-28T20:35:23.745568 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ufw/+bug/1871261/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp