Trying to upgrade

[charta.liber]

running sudo do-release-upgrade

stops:

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.

Restoring original system state

Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done

--------------------------

My OS info:
NAME="Ubuntu"
VERSION="20.04.5 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.5 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.39
Uname: Linux 5.18.10-76051810-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.25
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
Date: Sun Feb 5 17:51:24 2023
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to focal on 2023-02-05 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2023-02-05 17:51:00.009936
 Log time: 2023-02-05 17:51:04.858091
 Log time: 2023-02-05 17:51:24.139718
 Log time: 2023-02-05 17:51:25.460965

[Chris Guiver (guiverc)]

Thank you for reporting this bug to Ubuntu.

Bug reporting is about finding & fixing problems thus preventing future users from hitting the same bug.

I suspect a Support site would be more appropriate, eg. https://answers.launchpad.net/ubuntu. You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org, or for more support options please look at https://discourse.ubuntu.com/t/community-support/709