do-release-upgrade crashes with dependency problems systemd needs libgcrypt20 (>= 1.6.1)

[Winfried PLappert]

installed my production system in a VirtualBox environment. Upgrade from 1510 to 1604 (Beta2+) via
do-release-upgrade -d.

1.) lsb_release -rcid
Distributor ID: Ubuntu
Description: Ubuntu Xenial Xerus (development branch)
Release: 16.04
Codename: xenial

2.) uname -r: 4.2.0-35-generic

3.) /var/log/dist-upgrade/apt-term.log ends with:
...
Setting up libcap2:i386 (1:2.24-12) ...
dpkg: dependency problems prevent configuration of systemd:
 systemd depends on libgcrypt20 (>= 1.6.1); however:
  Package libgcrypt20:amd64 is not configured yet.

dpkg: error processing package systemd (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 systemd
Log ended: 2016-04-10 10:00:34

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:15.10.14.4
ProcVersionSignature: Ubuntu 4.2.0-35.40-generic 4.2.8-ckt5
Uname: Linux 4.2.0-35-generic x86_64
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CrashDB: ubuntu
Date: Sun Apr 10 10:36:55 2016
InstallationDate: Installed on 2016-04-07 (3 days ago)
InstallationMedia: Ubuntu-Server 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_IE:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_IE.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: release-upgrade
UpgradeStatus: Upgraded to xenial on 2016-04-10 (0 days ago)

[Winfried PLappert (winfried-plappert)]

dpkg -l filtered for outpit != ^ii
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture
+++-=====================================-==========================================-============
iU console-setup 1.108ubuntu13 all
iU curl 7.47.0-1ubuntu2 amd64
iU initramfs-tools 0.122ubuntu6 all
iU klibc-utils 2.0.4-8ubuntu1 amd64
rc libmwaw-0.3-3v5 0.3.5-1ubuntu1 amd64
rc libodfgen-0.1-1v5 0.1.4-1ubuntu1 amd64
rc perl-modules 5.20.2-6ubuntu0.2 all
iU plymouth 0.9.2-3ubuntu11 amd64
iU plymouth-label 0.9.2-3ubuntu11 amd64
iU plymouth-theme-ubuntu-mate-text 16.04.6 all
iU plymouth-theme-ubuntu-text 0.9.2-3ubuntu11 amd64
iF systemd 229-4ubuntu1 amd64

[Winfried PLappert (winfried-plappert)]

I can recover the upgrade by rebooting and patiently applying "sudo apt-get dist-upgrade" and following the suggestions on the screen. But the upgrade should be able to run error free -- by changing the sequence of installing certain dependencies.

libgcrypt20:amd64 only depends on lib6 and libpgp-error0, which in itself only depends on libc6.

[Winfried PLappert (winfried-plappert)]

I have done some more testing:
1.) I removed all the i386 packages, used for skype and google-earth and did a 'do-release-upgrade -d' -- and it worked.
2.) I rerun the 'do-release-upgrade -d' with the i386 packages still installed and it failed. with systemd being affected.