Ubuntu – Upgrading from 12.04.3 LTS to 14.04.1 LTS failure

12.0414.04hardware-enablement-stackupgrade

This has probably been asked millions of times already, but I'm struggling to update my Ubuntu system from LTS to LTS, now that the upgrade to 14.04.1 is out. My system keeps notifying me to upgrade to the latest release, claiming that 

Your current Hardware Enablement Stack (HWE) is going out of support
on 2014-08-07.  After this date security updates for critical parts (kernel
and graphics stack) of your system will no longer be available.`

However, when I run sudo do-release-upgrade, Ubuntu says I have no updates available. In addition, changing the prompt parameter in /etc/update-manager/release-upgrades to prompt=normal instead of prompt=lts throws the following error:

Checking for a new Ubuntu release
404  Not Found [IP: 91.189.91.14 80]
Err Upgrade tool
404  Not Found [IP: 91.189.91.14 80]
Fetched 0 B in 0s (0 B/s)
WARNING:root:file 'quantal.tar.gz.gpg' missing
Failed to fetch
Fetching the upgrade failed. There may be a network problem.

This seems weird to me as Quantal isn't even the current release, so I don't know why the system would be looking for it.

People have suggested appending the -d flag to the do-release-upgrade command, but the documentation says that this will install the development version of 14.04 which I don't want.

Any help would be appreciated to get me around this roadblock.

Best Answer

You have to reinstall the update manager. First, remove/purge it:

sudo apt-get purge update-manager-core update-notifier-common

Then have a look at the console output. If it tells you, that some directories could not be removed, delete them manually. In my case:

rm -rf /var/lib/update-manager
rm -rf /var/lib/update-notifier

If you are on 13.04 or later, you should also do this to clear cached update messages:

sudo rm /var/lib/ubuntu-release-upgrader/release-upgrade-available

Then update your sources:

sudo apt-get update

Reinstall the update manager:

sudo apt-get install update-manager-core update-notifier-common -y

Only if you are currently on an LTS and want to upgrade to latest LTS, make sure that in /etc/update-manager/release-upgrades you have set:

Prompt=lts

Otherwise (upgrading any version to a newer version) set:

Prompt=normal

Now dist-upgrade should work:

sudo apt-get dist-upgrade
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