On dist-upgrade from 17.10 to 18.04: package libstdc++6:amd64 8-20180414-1ubuntu2 failed to install/upgrade: package libstdc++6:amd64 is already installed and configured

Dist-upgrade broke my 17.10.

Due to the libstdc++6 not installed, a few dozen or so packages also failed to install (strangely enough with the same message -- "already installed and configured").

After the upgrade, which was reported as failed, my system was left in a broken state -- missing at least openssl, so apt-get, wget, and curl wouldn't work. Thankfully I had an open shell, and via python shell was able to download locale, libc6, libc6-bin, libssl, (maybe a few other packages) and install those using dpkg.

Only after this and a few apt update/apt --fix-broken/apt upgrades I was able to restore the OS
back into the working state.

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: libstdc++6:amd64 8-20180414-1ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
AptTermLog:

AptdaemonVersion: 1.1.1+bzr982-0ubuntu19
Architecture: amd64
CrashReports:
 640:0:114:492705:2018-04-28 20:43:53.708913564 +0300:2018-04-28 20:43:54.708913564 +0300:/var/crash/libstdc++6:amd64.0.crash
 640:0:114:492703:2018-04-28 20:43:54.728913265 +0300:2018-04-28 20:43:54.708913547 +0300:/var/crash/libstdc++6:i386.0.crash
Date: Sat Apr 28 20:43:54 2018
Dependencies:
 gcc-8-base 8-20180414-1ubuntu2
 libc6 2.27-3ubuntu1
 libgcc1 1:8-20180414-1ubuntu2
DpkgLog:

DuplicateSignature:
 package:libstdc++6:amd64:8-20180414-1ubuntu2
 Setting up liblz4-1:i386 (0.0~r131-2ubuntu3) ...
 dpkg: error processing package libstdc++6:amd64 (--configure):
  package libstdc++6:amd64 is already installed and configured
ErrorMessage: package libstdc++6:amd64 is already installed and configured
InstallationDate: Installed on 2014-04-02 (1489 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: dpkg
Title: package libstdc++6:amd64 8-20180414-1ubuntu2 failed to install/upgrade: package libstdc++6:amd64 is already installed and configured
UpgradeStatus: Upgraded to bionic on 2018-04-28 (2 days ago)