release upgrade from 18.04 to 18.10 cannot calculate upgrade, no reason given

[Russell Neches]

do-release-upgrade cannot calculate the upgrade, offers no useful insight as to why, and provides no way to see the actual underlying error.

====

Reading cache

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Hit http://us.archive.ubuntu.com/ubuntu bionic InRelease
Hit http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease
Hit http://security.ubuntu.com/ubuntu bionic-security InRelease
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done

Updating repository information
Hit http://security.ubuntu.com/ubuntu cosmic-security InRelease
Hit http://us.archive.ubuntu.com/ubuntu cosmic InRelease
Hit http://us.archive.ubuntu.com/ubuntu cosmic-updates InRelease
Hit http://us.archive.ubuntu.com/ubuntu cosmic-backports InRelease
Fetched 0 B in 0s (0 B/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 Oct 18 21:53:52 2018) ===

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.27
ProcVersionSignature: Ubuntu 4.15.0-36.39-generic 4.15.18
Uname: Linux 4.15.0-36-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.4
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: GNOME
Date: Thu Oct 18 21:49:00 2018
InstallationDate: Installed on 2015-12-17 (1036 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2018-10-19 (0 days ago)
mtime.conffile..etc.update-manager.release-upgrades: 2018-10-18T21:43:55.313922

[Launchpad Janitor (janitor)]

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

[Brian Murray (brian-murray)]

The following packages seem to be leftover from an old release of Ubuntu which you were running. Could you try using 'sudo apt autoremove' to see if they are removed automatically or try removing them manually and then upgrading? Thanks in advance.

From VarLogDistUpgradeMain.log:

emacs24-common emacs24-common-non-dfsg emacs24-lucid

[Russell Neches (ubuntu-vort)]

autoremove doesn't do the trick.

==

$ sudo apt-get autoremove
[sudo] password for russell:
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

==

Removing emacs24-lucid directly allows do-release-upgrade to work. Neat!

That error message should probably be amended to point users to log files in /var/log/dist-upgrade. I've been using Debian-based distros since before Ubuntu existed, and I had no idea it existed!

[Launchpad Janitor (janitor)]

[Expired for ubuntu-release-upgrader (Ubuntu) because there has been no activity for 60 days.]