Originally Posted by TobiSGD
I would strongly recommend to use a net-based upgrade path. I simply don't see the point in downloading DVDs instead of only the packages you need, especially if you only need one or two packages from a DVD. You also will not have to guess which DVDs you really need to upgrade your system.
Firstly, my thanks to both "frankbell" and "TobiSGD" for the prompt replies and "frankbell's" helpful reference.
The reference - alas - came too late; I had already printed out a 20-page extract of Debian's release notes!
However, nothing has been lost; the release notes point to the need to remove non-Debian packages before attempting the upgrade.
Based on my *unreliable* memory, I have 2 such packages (from Epson) that need to be removed.
The details provided by "dpkg-query" are:
dpkg-query -l "iscan*"
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
in iscan <none> (no description available)
pn iscan-plugin-g <none> (no description available)
- which raises more questions than it answers.
The new questions are:
1. Is there any (dpkg?) routine that would identify other alien packages on my system, that I had overlooked; and
2. Is "dpkg -r 'Package Name' " an adequate routine for (temporarily) removing the alien packages?
It is worth flagging that neither the "iscan" package nor the "iscan-plugin" were found by either aptitude or synaptic; the packages were supplied by Epson as ".rpm" packages and converted to ".deb" packages with the help of "alien".
Again, many thanks for the helpful advice.