It appears the installer was asking a question and perhaps the GUI failed to display it for you. It got no answer, which is a minor problem in the update installer and not a bug in gdm3.
Configuration file '/etc/gdm3/custom.conf' ==> 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. *** custom.conf (Y/I/N/O/D/Z) [default=N] ? dpkg: error processing package gdm3 (--configure): end of file on stdin at conffile prompt -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm3 in Ubuntu. https://bugs.launchpad.net/bugs/1900694 Title: package gdm3 3.36.3-0ubuntu0.20.04.1 failed to install/upgrade: end of file on stdin at conffile prompt To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1900694/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs