Try to upgrade from 14.04 LTS to next version 15.04 (after switched from LTS to any new Version in the updater tool)

[karandras]

After I have switched from LTS (14.04) to update channel (any new version), I had clicked on upgrade (in the upgrader tool) to 15.04 (after a restart).

The upgrader tool check for new software and tried to set new software channels in a second step. During this the error message raised. The Upgrade failed and my system were set back to 14.04.

Additional:

Under /etc/apt/ the updater process had added new sources.lists (after the roll back as sources.list.distUpgrade) for the dist-upgrade and for my comprehension they seem correct.

Details:

Description: Ubuntu 14.04.3 LTS
Release: 14.04

Hope this helps to locate the issue.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.8
ProcVersionSignature: Ubuntu 3.13.0-74.118-generic 3.13.11-ckt30
Uname: Linux 3.13.0-74-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
CrashDB: ubuntu
Date: Mon Jan 18 21:03:38 2016
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2016-01-18 (0 days ago)
VarLogDistupgradeTermlog:

mtime.conffile..etc.update.manager.release.upgrades: 2016-01-15T10:21:24.008473

[Launchpad Janitor (janitor)]

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

[Brian Murray (brian-murray)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1534374, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.