Ubuntu failed to upgrade from Ubuntu 20.04 LTS to 20.10

[Henrique Mendonça]

This is the output of the terminal when I tried to upgrade from Ubuntu 20.04 LTS to Ubuntu 20.10:

$sudo do-release-upgrade

Checking for a new Ubuntu release
Get:1 Upgrade tool signature [819 B]
Get:2 Upgrade tool [1.338 kB]
Fetched 1.339 kB in 0s (0 B/s)
authenticate 'groovy.tar.gz' against 'groovy.tar.gz.gpg'
extracting 'groovy.tar.gz'

Reading cache

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

Livepatch security updates are not available for Ubuntu 20.10. If you
upgrade, Livepatch will turn off.

Continue [yN] y
Hit https://dl.google.com/linux/chrome/deb stable InRelease
Hit http://archive.canonical.com/ubuntu focal InRelease
Ign https://dl.google.com/linux/earth/deb stable InRelease
Hit https://dl.google.com/linux/earth/deb stable Release
Hit https://updates.signal.org/desktop/apt xenial InRelease
Hit https://packages.microsoft.com/ubuntu/20.04/prod focal InRelease
Get:1 http://mirrors.ubuntu.com/mirrors.txt Mirrorlist [373 B]
Hit http://mirror.ufscar.br/ubuntu focal-updates InRelease
Hit http://repositorio.nti.ufal.br/ubuntu focal-security InRelease
Hit http://ubuntu-archive.locaweb.com.br/ubuntu focal InRelease
Hit http://archive.ubuntu.com/ubuntu focal-backports InRelease
Fetched 373 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done

Checking for installed snaps

Calculating snap size requirements

Updating repository information

Third party sources disabled

Some third party entries in your sources.list were disabled. You can
re-enable them after the upgrade with the 'software-properties' tool
or your package manager.

To continue please press [ENTER]

Get:1 http://archive.canonical.com/ubuntu groovy InRelease [11,4 kB]
Get:2 http://archive.canonical.com/ubuntu groovy/partner amd64 Packages [1.292 B]
Get:3 http://archive.canonical.com/ubuntu groovy/partner Translation-en [540 B]
Fetched 13,2 kB in 0s (0 B/s)

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

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.28
ProcVersionSignature: Ubuntu 5.4.0-52.57-generic 5.4.65
Uname: Linux 5.4.0-52-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.10
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
Date: Sun Oct 25 08:36:33 2020
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to focal on 2020-10-25 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2020-10-25 08:36:13.201648
 Log time: 2020-10-25 08:36:17.314341
 Log time: 2020-10-25 08:36:32.886024
 Log time: 2020-10-25 08:36:34.697674
mtime.conffile..etc.update-manager.release-upgrades: 2020-10-25T08:19:53.203973

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.