After updating your package information, the essential package 'ubuntu-minimal' could not be located.

[valeras]

release upgrade 16.04 to 18.04 stopped due to 'After updating your package information, the essential package 'ubuntu-minimal' could not be located.'

further installation of ubuntu-minimal fails because of the package is present

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.32
ProcVersionSignature: Ubuntu 4.15.0-142.146~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-142-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.30
Architecture: amd64
CrashDB: ubuntu
Date: Sat Jun 12 14:55:42 2021
InstallationDate: Installed on 2017-09-09 (1371 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to xenial on 2021-06-12 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2021-06-12 14:55:11.636484
 Log time: 2021-06-12 14:55:15.577442
 Log time: 2021-06-12 14:55:42.440471
 Log time: 2021-06-12 14:55:44.713797

[Chris Guiver (guiverc)]

Thanks for your bug report and for your contribution to Ubuntu.

Could you please add the /var/log/dist-upgrade/apt.log file from your upgrade attempt to the bug report as an attachment? Thanks in advance.