http://www.sane-project.org/sane-backends.html#SCANNERS

I use FerenOS whilst working from Home (Plasma DE) and can't get it to work in that OS either - I ended up purchasing hamrick's vue-scan. (I have the Canon Linux Scanner driver but the interface is pants compared to X-Sane and Simple (/Document) Scan (/ner)

python-dbus.mainloop.pyqt5
python-pyqt5
python-qt4
python-qt4-dbus
python3-dbus
python3-dbus.mainloop.pyqt5

Sorry, my fault ...
The package name is python3-pyqt4. 

It's quite allright.
No problem.  8^D

Cheers,

A.

Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package pyqt4

In the interest of completeness, I did not first uninstall hplip 16. Now I'm glad I didn't.

All parts are pertinent.

OK

You did not purge the previous HPLIP version before trying to install 3.19.5?

I have seen at least two posts on the web where it was said that the previous package had to be cleared out.
Can't find them now but I think you should do that.

Purge the installed version of HPLIP, reboot, make sure your installation is up to date and that there are no missing dependencies.

# apt autoremove --purge hplip

# apt update && apt upgrade && apt install -f

Reboot.
Now try to install the missing dependencies.

From your post I see that the HPLIP installer says it needs pyqt5 and pyqt5-dbus.
But when it tries to install them it bitches about pyqt4 and pyqt4-dbus and crashes.

Does not take into account the dependencies of the dependencies.  8^D

Let's try to install the missing dependencies individually, one by one via apt on the terminal.
Not via the HPLIP installer, evidently it is rather lacking.

ie:

# apt install pyqt4-dbus   <---- *first* the ones that are needed to be able to install the ones HPLIP says it needs
# apt install pyqt4

# apt install pyqt5-dbus   <---- *then* the ones that HPLIP says it needs
# apt install pyqt5

Then, just in case, check for other missing dependencies or updates.
ie:

# apt update && apt upgrade && apt install -f

Stop there (don't install HPLIP yet) and let us know how it went.

Cheers,

A.

MISSING DEPENDENCIES
--------------------
Following dependencies are not installed. HPLIP will not work if all REQUIRED dependencies are not installed and some of the HPLIP features will not work if OPTIONAL dependencies are not installed.
Package-Name         Component            Required/Optional   
pyqt5-dbus           gui_qt5              OPTIONAL            
pyqt5                gui_qt5              REQUIRED  

I type "y" and press enter. Then a bit later I get this...

DEPENDENCY AND CONFLICT RESOLUTION
----------------------------------
Running 'su -c "apt-get install --force-yes -ygtk2-engines-pixbuf" '
Please wait, this may take several minutes. . .
Running 'su -c "apt-get install --force-yes -y python-pyqt5" '
Please wait, this may take several minutes. . .
Running 'su -c "apt-get install --force-yes -y python-dbus.mainloop.pyqt5" '
Please wait, this may take several minutes. . .
error: A required dependency 'pyqt4-dbus (PyQt 4 DBus - DBus Support for PyQt4)' is still missing.
error: A required dependency 'pyqt4 (PyQt 4- Qt interface for Python (for Qt version 4.x))' is still missing.

Then a few seconds later, the terminal crashes and I'm still on hplip 3.16.11.

At this point, I'm just afraid to go on thinking that I might lose the printing function with all this fiddling around.

I assume it is after, which is when dependency hell has broken loose.  8^D.
Let's see if we can find a way out of this.

First purge the previous version of HPLIP.

As root: apt purge autoremove hplip

Reboot and try to install HPLIP 3.19.5 you got from HP (I assume it is a *.deb file?)

Post the output so we can see what's going on dependency wise.

Maybe they are just one or two libraries and you can install them via apt with no issues and then try to install HPLIP 3.19.5 again.
Or maybe they cannot be installed because those dependencies also have their own dependencies to complain about and it goes on.

Edit
Q:
Is it absolutely necessary to install HPLIP to get the scanner/printer working?
A couple of years ago I needed to get a printer to use at home asap and landed an inexpensive Samsung M2020W.
HPLIP was a hellish experience and then I came across CUPS. No issues ever again.

Cheers,

A.

On top of every page in this forum on the right hand side you find 5 links. The one to the right says Packages.

Open that link, enter hplip* in the box and select Any as release. You get a list of entries across all Devuan versions.

In Beowulf on 3.18.12 is present. No backports version. You may try the 3.20 from Ceres. Somewhere in this forum is a howto how to avoid pulling all kinds of stuff from the Ceres repo.

rolfie

This is HPLIP from the Debian Bullseye repository.
As far as I understand it, it is not a backport.

Have you tried apt install -f to see if you could fix the dependency problems when installing HPLIP 3.19.5?

That's the only thing I can think of.

Cheers,

A.

I found this: https://packages.debian.org/bullseye/hplip

I have not found it there.

The debian Stretch backport is hplip-gui 3.18.12+dfsg0-2~bpo9+1

I stand correcetd.
Indeed, the squiggles are due to the spellchecker.
I don't use automatic spell checking.

But there was a time when, if you entered Devuan in the Google search engine, it would invariably ask if you had not meant Debian.
Not the case any longer.  8^D

Cheers,

A.

https://pkginfo.devuan.org/cgi-bin/d1pk … elease=any

Have you looked in ascii backports?  Might not need to upgrade to beowulf.

It is your spellchecker that is objecting to Devuan. Just add that word and the red squiggle will go away.

Looked in the backports (here; is this the right place?), and it only goes up to hplip version 3.18.12. According to the hplip site I need version 3.19.5. So am I SOL with using my scanner? Is there any other possible way to get it working??

Offtopic: Added "Devuan" to spellchecker. Thanks golinux.