boot process hangs at partition file clean notice

[nvsoar]

Dell XPS8300; Win 10; latest Ubuntu 19.10 version as of 1851 PDT on 21Aug2019
Work around is to enter alt f2 followed by alt f1, whereupon the long in screen appears.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: ubuntu-release-upgrader-core 1:19.10.10
ProcVersionSignature: Ubuntu 5.2.0-10.11-generic 5.2.4
Uname: Linux 5.2.0-10-generic x86_64
ApportVersion: 2.20.11-0ubuntu7
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Wed Aug 21 18:42:48 2019
InstallationDate: Installed on 2019-07-03 (49 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Alpha amd64 (20190606)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: release-upgrade
UpgradeStatus: No upgrade log present (probably fresh install)
VarLogDistupgradeTermlog: