This is still broken as of today.
Tried to upgrade a fully up-to-date 1604 LTS system to 1804 LTS using "do-release-upgrade" and it failed with this exact issue.
Had to use the steps from comment #3 above to get it working...
mv /usr/share/dbus-1/system-services/org.freedesktop.systemd1.service /usr/share/dbus-1/system-services/org.freedesktop.systemd1.service.bak apt-get -f install apt-get dist-upgrade
This is still broken as of today.
Tried to upgrade a fully up-to-date 1604 LTS system to 1804 LTS using "do-release- upgrade" and it failed with this exact issue.
Had to use the steps from comment #3 above to get it working...
mv /usr/share/ dbus-1/ system- services/ org.freedesktop .systemd1. service /usr/share/ dbus-1/ system- services/ org.freedesktop .systemd1. service. bak
apt-get -f install
apt-get dist-upgrade