hplip 3.18.4 on ubuntu 10.04

First I tried to install hplip from the Ubuntu repository but after installation I found none of the hp-* programs. The links in /usr/bin all point to /usr/share/hplip/xxx.py but these file were all misssing.
Then I downloaded hplip-3.18.4.run but when installing it complained a missing /usr/lib/cups/backend/hpfax.
I could not find this file on the HP WEB site and I copied a version from my Ubuntu 16.04 distribution. This allowed to run through the installation completely but the files /usr/share/hplip/xxx.py were still not there.
I also copied those from Ubuntu 16.04 but when running e.g. hp-doctor it tells me that Ubuntu 18.04 is not supported.
Now, when running hp-setup, this is what I get:

Traceback (most recent call last):
  File "/usr/bin/hp-setup", line 45, in <module>
    from base import device, utils, tui, models, module, services, os_utils
  File "/usr/share/hplip/base/device.py", line 41, in <module>
    from . import status
  File "/usr/share/hplip/base/status.py", line 32, in <module>
    import cupsext
ImportError: libhpipp.so.0: failed to map segment from shared object
Error in sys.excepthook:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 145, in apport_excepthook
    os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o640), 'wb') as f:
PermissionError: [Errno 13] Permission denied: '/var/crash/_usr_share_hplip_setup.py.1000.crash'

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/hp-setup", line 45, in <module>
    from base import device, utils, tui, models, module, services, os_utils
  File "/usr/share/hplip/base/device.py", line 41, in <module>
    from . import status
  File "/usr/share/hplip/base/status.py", line 32, in <module>
    import cupsext
ImportError: libhpipp.so.0: failed to map segment from shared object

In addition the systray does not work in Gnome-3