unable to upgrade kubuntu-minimal from 18.04 to 18.10

[Ian Truelsen]

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done

Invalid package information

After updating your package information, the essential package
'ubuntu-minimal' could not be located. This may be because you have
no official mirrors listed in your software sources, or because of
excessive load on the mirror you are using. See /etc/apt/sources.list
for the current list of configured software sources.
In the case of an overloaded mirror, you may want to try the upgrade
again later.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.33
ProcVersionSignature: Ubuntu 4.15.0-50.54-generic 4.15.18
Uname: Linux 4.15.0-50-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CrashDB: ubuntu
Date: Sun May 26 07:18:24 2019
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2019-05-26 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2019-05-26 07:17:53.229390
 Log time: 2019-05-26 07:17:57.199473
 Log time: 2019-05-26 07:18:23.868260
 Log time: 2019-05-26 07:18:26.013243
mtime.conffile..etc.update-manager.release-upgrades: 2019-05-23T07:06:13.491122