interrupted release upgrade may confuse update-manager into believing an upgrade is not necessary

[LantzR]

About halfway through getting new packages (1,017+ of 2,045), in an Distribution Upgrade (`sudo update-manager -d`) to 14.04, I lost my wireless access connection.
The net access had been flaky and I hold Ubiquity blameless in the dropped connection.

The issue was I was unable to get Ubiquity to continue on. About this system still showned 13.10 and `update-manager -d` stated there where no updates. I kinda expected a restart to pick up the ball but it didnot, nor did a full power restart.

I am not in any position to be able to recreate the issue, though I believe that just pulling the network connection while the system is fetching files will manifest what happened to me.

I had been logging the progress of the file being fetched prior to losing the connection. My last manual entry was recording that Ubiquity was "Fetching file 1,083 of 2,045 at a blazing 217 kB/s "

- - - - - - - - - - - - - -

Trusty Tahr (14.04 LTS)
- Getting new Packages
 - Fetching file \

0849 - 25 at 57.8 kB/s - of 2,045
0912 - 343 at 54.7
0946 - 694 at 66.4 kB/s
1017 - 1083 at 217 kB/s
- - - - - - - - - - - - - -

Cheers,
Lantz

--
  Think Different! Think YottaHertz!
  Lantz Rowland <email address hidden>

ProblemType: BugDistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.2
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Thu Apr 17 00:08:39 2014
InstallationDate: Installed on 2014-03-28 (19 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
PackageArchitecture: allSourcePackage: ubuntu-release-upgrader
Symptom: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2014-04-13 (3 days ago)

[LantzR (lantzr)]

btw the "work around" was to follow instruction to do a distribution upgrade for servers to get to 14.04.

[LantzR (lantzr)]

[More complete version of comment #2 above]

My workaround to finish installing 14.04 Tahr, with (System Settings... -> Details ) showing I was still on 13.10 and 'update-manager -d' saying there was nothing to upgrade as I described above, was to use the distribution upgrade for servers:

    `sudo do-release-upgrade -d`

That took me successfully to 14.04

https://help.ubuntu.com/12.04/serverguide/installing-upgrading.html

For me personally the issue with `sudo update-manager -d` being unable to finish was a paper scratch , a surprise as I expected both a rerun or a restart to continue where it left off. Most human clients if they get caught in this rare net drop situation would get seriously stuck and the work around of switching to do-release-upgrade is not intuitively obvious .