Interrupted Upgrade from Ubuntu 9.10 to 10.04 (Lucid Lynx)

Using Update Manager, I was downloading an upgrade from Ubuntu 9.10 to 10.04 (Lucid Lynx) on my laptop.  I had to interrupt it.  When I started the laptop again and tried to resume the upgrade, I had problems.  For one thing, I wasn’t located in a place with wireless, and my wired ethernet connection was not working.  I had already downloaded the remaining upgrade packages at a wireless location, though, so I hoped it would be just a matter of starting the computer and installing those updates.  This, unfortunately, was not the case.  It seemed I had completely screwed up the Ubuntu kernel, and therefore had to choose an older kernel to install from in GRUB.  Then, when I went into System > Administration > Update Manager, I began to learn that my problems had only begun.

What I got, in Update Manager, was this message:

Not all updates can be installed.

Run a partial upgrade, to install as many updates as possible.

I clicked on the Partial Upgrade button.  This led to another message:

Broken packages

Your system contains broken packages that couldn’t be fixed with this software.  Please fix them first using synaptic or apt-get before proceeding.

I went into System > Administration > Synaptic Package Manager.  It said this:

You have 7 broken packages on your system!

Use the “Broken” filter to locate them.

In Synaptic, I went to Edit > Fix Broken Packages.  This said:

An error occurred.

The following details are provided:

E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages

E: Unable to correct dependencies

I clicked Reload.  Synaptic was not able to download package information.  I canceled that.  I got a new message:

Could not download all repository indexes.

The repository may no longer be available or could not be contacted because of network problems.

I closed that.  Synaptic’s status bar said, “30190 packages listed, 1277 installed, 0 broken, 135 to install/upgrade, 7 to remove; 51.6 MB will be used.”  That sounded good.  I clicked Apply.  It asked me, “Apply the following changes?”  It had a warning:  “You are about to install software that can’t be authenticated!”  If it had been one or two items, I might have thought twice, but it was dozens of packages, some of which (e.g., seed) even had community documentation.  So I disregarded that warning.  Again, Synaptic tried to download package files and couldn’t, and it wouldn’t go any further until that was done.  So at this point I hibernated the Ubuntu installation and used the laptop solely in Vista mode until I could work through the ethernet problem or go to a wireless location again to continue.

When I did get back to this situation, I tried a number of solutions but ultimately was not able to recover from the interrupted upgrade process.  I therefore started over:  I used an Acronis True Image backup to restore Ubuntu 9.10 and then tried the upgrade again from there.