I originally switched to Debian in the hope of having a stable platform (like with Ubuntu 10.04 & 12.04).

That hasn't been the case to date, though as a side effect I've learned a lot about package dependency and a fair bit about system administration.

It is from this point of view, that I will defer to the judgement of those who have more experience and wait until jessie is upgraded to stable. The wiki states the release date is 25.04.2015 and I guess I can wait that long. I have enough other issues to worry about... like a non-functioning ipcop and a DB that I need to set up.

Hmmm... time to make some backups!

Thanks for the input, people. I will post the results of the upgrade as realates to the HP scanner.

Ciao.

The update is complete. I didn't notice any special messages pertaining to the HP L7590. So I assumed the update would achieve the desired result... ie, that my scanner would work. Unfortunately, it hasn't worked out that way.

I get the same error as before when I try to use Xsane Image Scanner:
So I wen to synaptic to make a quick check of the package being used and discovered it was the old one: hplip 3.12.6. To find out what was wrong, I tried telling synaptic to perform the upgrade. This resulted in the error message: When I list the broken packages I find libcairo2 and libglib2.0-0. The logical action was to try telling synaptic to fix the broken packages. This resulted in the following:

Next I tried to find out what held packages I actually have using the command
This listed nothing at all. So I eyeballed the entire list and indeed there were no held packages listed. I also noticed that libcairo2 is not listed at all. Same applies for libglib2.0-0. In both case I find the package listed with the extension ":amd64" and this is probably the problem, because it suggests an incompaitbility between hplip (probably a 32 bit module) and the two "broken" packages. I am unsure how to fix it, though. I'm not even sure that my interpretation is correct.

Any advice is greatly appreciated.

I think you have a screwed Wheezy install and should start over with a clean Jessie install. Avoid backports this time. Debian offers backports but a Stable install does not meet the Debian definition of Stable. Of coarse, to be fair, one with contrib and nonfree repos enabled doesn't either really. I certainly use the contrib and nonfree and the multi media repo.

What I would do, short of a clean Jessie install, is;
Quit fooling with more than one package. This can only make things more difficult.

Do not use Synaptic, use the cli.

Comment out the backports repo, can be reset later.

Purge ALL packages having to do with HP.

Check your ~/.foo file for user config files for anything to do with HP and delete them. Purge will get the system config files but not the user land config files.

Install the HP packages.

I am a big fan of apt-get and use it most of the time. Since Wheezy it has actually been safe to use aptitude and apt-get due to changes in how aptitude deals with package state being changed to be compatible with apt-gets dealing with package state.

I would use aptitude in all these procedings. It will, if dependencies resolution problems persist, list them and alternatives for dealing with them. You will be given the choice of accepting or declining the alternative. Do this until you have seen them all and it says that is all of them. Pay attention to them all. One will be better for your system, in your oppinion than the others. Simply start over and go to that alternative and use it.

Make sure you look at packages removed and save all of that for future use in getting your system back to normal after resolving this problem.

Thanks for the advice widget. I'll bear it in mind for future reference. It might, however, not be required at this stage.

Late last night I "fooled around" as you so aptly put it. I wanted to see what the state of my install actually was. For the sake of the record I used these instructions when doing the original upgrade to jessie.

The easiest way to examine the state of a current install ist to check it out with synaptic (yes, I'm lazy). I went through the various filters and, see there, there were dozens of pakages listed as "upstream upgradeable". So whilst my system was telling me I had sucessfully upgraded, in fact it was only half done (or so it seemed to me).

Since I had all the backups I needed to restore from a fresh install, I figured I could risk screwing my upgrade install up. Without hesitation I marked all available upgrades and told synaptic to get on with it (i.e. clicked "apply"). The resulting install lasted about as long as the original upgrade. There were two questions about packages which were not required (or some such thing) and I chose to skip over those. Apart from that it all went smoothly.

There are no onger any broken packages. One package is still listed as upgradeable: libboost-iostreams-dev. Since I don't do any C++ development (at least not yet) I can probably ignore it. I still need to check various functions, but the quick launch icons seem to be working as is the WLAN interface, caja file manager, evolution e-mail, and so on. Oddly enough, Synaptic no longer works from the System > Administration menu. I have to start it from the command line.

Of course I checked the scanner with Xsane and it works! So does simple scan.

I will mark this thread as solved, since the original problem - not being able to update the hplip package - has been resolved. Even if it is a bit like shooting mosquitoes with a shotgun.

Thanks for your thoughts and tips everyone.