I try to install hplip-3.18.9 on bionic 18.04 (actually NEON). The installer complains about missing dependencies:
Package-Name | Component | Required/Optional
dbus | fax | REQUIRED
The package dbus 1.12.2-1ubuntu1 is the newest version and installed.
Linux NEON is also uptodate.
So how can I convince hplip to find dbus ?
Thank you for your help.

Do you have python-dbus installed? Hplip uses python for all sorts of things. It might not be able to access dbus without it.

is installed ; version 1.2.6-1

Well, it could be anything really..
What distro do you use?

I've had troubles with HPLIP many times before due to it not installing dependencies that are required and not handling some necessary settings that you have to adjust to get it working.

There are tools in HPLIP as far as I rememeber, to check if all dependencies are installed. If they are not, you will not get any particular details if HPLIP does not work due to this issue. The list of dependencies for HPLIP is quite clear on which dependencies it needs. So try to install all of those.

I am sorry I cannot be more helpful, but it is a long time since I had these issues and I can not remember the direct commands etc to solve the issues.

Hello Zeebra,
thank you for taking your time ;-)
I am using Neon which is KDE on Ubuntu (bionic).
If I try to install manually I could resolve all the dependencies but not dbus. The hplip installer does not find dbus or is not able to use dbus.
Dbus is installed ! So I did not understand what I can do to fix this situation.

I installed hplip 3.17.10 from the repositories. I can print but not fax !

It could be to user groups. You have to make your user member of lp and lpadmin both most likely. Dbus is for KDE really and has reached more widespread adaptation.

You have to make sure you are member of the print group and whatever HP group if any.

My user is a member of lp and lpadmin.
There is a user hplip ...
The groups are : me + adm lp fax cdrom sudo dip plugdev lpadmin sambashare