What's even more curious is that in 15.10 systemd already depends on libgcrypt20, and 15.10 already has a new enough version, so I don't see an obvious reason why it should disappear during that part of the upgrade.
** Changed in: systemd (Ubuntu) Status: Confirmed => Incomplete ** Summary changed: - package systemd-sysv 225-1ubuntu9.1 failed to install/upgrade: pre-dependency problem - not installing systemd-sysv + package systemd-sysv 225-1ubuntu9.1 failed to install/upgrade: libgcrypt20 was unconfigured -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1560797 Title: package systemd-sysv 225-1ubuntu9.1 failed to install/upgrade: libgcrypt20 was unconfigured Status in systemd package in Ubuntu: Incomplete Bug description: Happened during upgrade to 16.04, don't know any more details. ProblemType: Package DistroRelease: Ubuntu 16.04 Package: systemd-sysv 225-1ubuntu9.1 Uname: Linux 4.4.5-040405-generic x86_64 ApportVersion: 2.20-0ubuntu3 Architecture: amd64 Date: Tue Mar 22 22:56:03 2016 ErrorMessage: pre-dependency problem - not installing systemd-sysv InstallationDate: Installed on 2013-04-24 (1064 days ago) InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130423.1) RelatedPackageVersions: dpkg 1.18.4ubuntu1 apt 1.2.7 SourcePackage: systemd Title: package systemd-sysv 225-1ubuntu9.1 failed to install/upgrade: pre-dependency problem - not installing systemd-sysv UpgradeStatus: Upgraded to xenial on 2016-03-23 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1560797/+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