upgrade from 12.04 LTS to 14.04 fails

[Dmitry Kan]

Please let me know, in case more information is needed on the sw / hw side. Thanks.

Description: Ubuntu 12.04.5 LTS
Release: 12.04

update-manager:
  Installed: 1:0.156.14.17
  Candidate: 1:0.196.12
  Version table:
     1:0.196.12 0
        500 http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ trusty-updates/main amd64 Packages
     1:0.196.11 0
        500 http://www.nic.funet.fi/pub/mirrors/archive.ubuntu.com/ trusty/main amd64 Packages
 *** 1:0.156.14.17 0
        100 /var/lib/dpkg/status

Instead of upgrading, the manager outputs:

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.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.17
ProcVersionSignature: Ubuntu 3.2.0-76.111-generic 3.2.66
Uname: Linux 3.2.0-76-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.8
Architecture: amd64
Date: Fri Jan 23 11:55:49 2015
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
Symptom: ubuntu-release-upgrader-core
UpgradeStatus: Upgraded to precise on 2015-01-23 (0 days ago)
VarLogDistupgradeTermlog:

[Ubuntu Foundations Team Bug Bot (crichton)]

You seem to have installed the cinnamon package on Ubuntu 13.10. Unfortunately, that package is not available yet for 14.04. To upgrade to Ubuntu 14.04 LTS you'll need to either wait for a fix for cinnamon to be available or uninstall the package and then upgrade.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Dmitry Kan (dmitry-kan)]

Uninstalling cinnamon package has helped to solve the issue. Thanks.

[Ubuntu Foundations Team Bug Bot (crichton)]

You seem to have installed the cinnamon package on Ubuntu 13.10. Unfortunately, that package is not available yet for 14.04. To upgrade to Ubuntu 14.04 LTS you'll need to either wait for a fix for cinnamon to be available or uninstall the package and then upgrade.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]