Release upgrader crashes while upgrading from 16.04LTS to 18.04 LTS

[Jaydeep Nandi]

I was trying to upgrade ubuntu 16.04 LST t 18.04 LTS. However, it fails giving the following information:

Get:50 http://in.archive.ubuntu.com/ubuntu bionic-updates/multiverse amd64 Packages [3,772 B]
Get:51 http://in.archive.ubuntu.com/ubuntu bionic-updates/multiverse i386 Packages [3,924 B]
Get:52 http://in.archive.ubuntu.com/ubuntu bionic-updates/multiverse Translation-en [2,376 B]
Get:53 http://in.archive.ubuntu.com/ubuntu bionic-updates/multiverse amd64 DEP-11 Metadata [2,464 B]
Get:54 http://in.archive.ubuntu.com/ubuntu bionic-updates/multiverse DEP-11 64x64 Icons [2,638 B]
Get:55 http://in.archive.ubuntu.com/ubuntu bionic-backports/universe amd64 Packages [2,704 B]
Get:56 http://in.archive.ubuntu.com/ubuntu bionic-backports/universe i386 Packages [2,704 B]
Get:57 http://in.archive.ubuntu.com/ubuntu bionic-backports/universe Translation-en [1,136 B]
Get:58 http://in.archive.ubuntu.com/ubuntu bionic-backports/universe amd64 DEP-11 Metadata [5,100 B]
Get:59 http://in.archive.ubuntu.com/ubuntu bionic-backports/universe DEP-11 64x64 Icons [1,789 B]
Fetched 40.2 MB in 6s (558 kB/s)

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

Calculating the changes

Calculating the changes

Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

This can be caused by:
* Upgrading to a pre-release version of Ubuntu
* Running the current pre-release version of Ubuntu
* Unofficial software packages not provided by Ubuntu

If none of this applies, then please report this bug using the
command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal.

Restoring original system state

Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
=== Command terminated with exit status 1 (Thu Aug 2 09:57:31 2018) ===

I removed the unofficial repositories ppa s from the repository list before the upgrade. Also, normal update runs fine in 16.04, so this is something that has to do with the repositories added by the release-upgrader tool.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.25
ProcVersionSignature: Ubuntu 4.4.0-112.135-generic 4.4.98
Uname: Linux 4.4.0-112-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: GNOME-Classic:GNOME
Date: Thu Aug 2 09:43:52 2018
InstallationDate: Installed on 2017-01-10 (568 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to xenial on 2018-08-02 (0 days ago)
mtime.conffile..etc.update-manager.release-upgrades: 2017-01-16T12:37:51.492631

[Brian Murray (brian-murray)]

This is in part due to the ubuntu-toolchain PPA you have enabled and installed packages from. Please use the tool 'ppa-purge' from the package 'ppa-purge' to disable that PPA and downgrade to the official Ubuntu versions of the packages provided by that PPA. After that you can try the upgrade again.

[Jaydeep Nandi (jayd-1234)]

It worked!

Thanks!