I have just done a clean installation of Ubuntu 20.04.1 on a Lenovo Yoga 730. I have a wireless HP Photosmart C4780 which I have setup successfully setup on another Ubuntu 20.04 and Ubuntu 18.04 machine by simply using

hp-setup 192.168.0.22

When I first logged in to the new installation I used

apt list --installed

which showed me that hplip and hplip-data were installed. I ran

apt install hplip-gui

and then tried

hp-setup 192.168.0.22

which fails with error

error:  Printer queue setup failed.   Error : successful-ok-ignored-or-substituted-attributes

To check what is wrong I ran

hp-doctor

which gives

HP Linux Imaging and Printing System (ver. 3.20.3)

Self Diagnse Utility and Healing Utility ver. 1.0



Copyright (c) 2001-18 HP Development Company, LP

This software comes with ABSOLUTELY NO WARRANTY.

This is free software, and you are welcome to distribute it

under certain conditions. See COPYING file for more details.





HP Linux Imaging and Printing System (ver. 3.20.3)

Self Diagnse Utility and Healing Utility ver. 1.0



Copyright (c) 2001-18 HP Development Company, LP

This software comes with ABSOLUTELY NO WARRANTY.

This is free software, and you are welcome to distribute it

under certain conditions. See COPYING file for more details.



 



Checking for Deprecated items....

No Deprecated items are found





Checking for HPLIP updates....

error: Failed to locate hp-upgrade utility





Checking for Dependencies....

warning: ubuntu-20.04 version is not supported. Using ubuntu-19.10 versions dependencies to verify and install...



---------------

| SYSTEM INFO |

---------------



 Kernel: 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 GNU/Linux

 Host: nell

 Proc: 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 GNU/Linux

 Distribution: ubuntu 20.04

 Bitness: 64 bit





-----------------------

| HPLIP CONFIGURATION |

-----------------------



HPLIP-Version: HPLIP 3.20.3

HPLIP-Home: /usr/share/hplip

warning: HPLIP-Installation: Auto installation is not supported for ubuntu distro  20.04 version 



Current contents of '/etc/hp/hplip.conf' file:

# hplip.conf.  Generated from hplip.conf.in by configure.



[hplip]

version=3.20.3



[dirs]

home=/usr/share/hplip

run=/var/run

ppd=/usr/share/ppd/hplip/HP

ppdbase=/usr/share/ppd/hplip

doc=/usr/share/doc/hplip

html=/usr/share/doc/hplip-doc

icon=no

cupsbackend=/usr/lib/cups/backend

cupsfilter=/usr/lib/cups/filter

drv=/usr/share/cups/drv

bin=/usr/bin

apparmor=/etc/apparmor.d

# Following values are determined at configure time and cannot be changed.

[configure]

network-build=yes

libusb01-build=no

pp-build=no

gui-build=yes

scanner-build=yes

fax-build=yes

dbus-build=yes

cups11-build=no

doc-build=yes

shadow-build=no

hpijs-install=yes

foomatic-drv-install=yes

foomatic-ppd-install=no

foomatic-rip-hplip-install=no

hpcups-install=yes

cups-drv-install=yes

cups-ppd-install=no

internal-tag=3.20.3

restricted-build=no

ui-toolkit=qt5

qt3=no

qt4=no

qt5=yes

policy-kit=yes

lite-build=no

udev_sysfs_rules=no

hpcups-only-build=no

hpijs-only-build=no

apparmor_build=no

class-driver=no





Current contents of '/var/lib/hp/hplip.state' file:

[plugin]

installed = 1

eula = 1

version = 3.20.3







Current contents of '~/.hplip/hplip.conf' file:

[last_used]

device_uri = hp:/net/Photosmart_C4700_series?ip=192.168.0.22



[installation]

date_time = 09/22/20 18:30:55

version = 3.20.3





 <Package-name>        <Package-Desc>      <Required/Optional> <Min-Version> <Installed-Version> <Status>   <Comment>



-------------------------

| External Dependencies |

-------------------------



 error: cups          CUPS - Common Unix Printing System                           REQUIRED        1.1             -               INCOMPAT   'CUPS may not be installed or not running'

 gs                   GhostScript - PostScript and PDF language interpreter and previewer REQUIRED        7.05            9.50            OK         -

 error: xsane         xsane - Graphical scanner frontend for SANE                  OPTIONAL        0.9             -               MISSING    'xsane needs to be installed'

 scanimage            scanimage - Shell scanning program                           OPTIONAL        1.0             1.0.29          OK         -

 error: dbus          DBus - Message bus system                                    REQUIRED        -               1.12.16         MISSING    'DBUS may not be installed or not running'

 policykit            PolicyKit - Administrative policy framework                  OPTIONAL        -               0.105           OK         -

 network              network -wget                                                OPTIONAL        -               1.20.3          OK         -

 avahi-utils          avahi-utils                                                  OPTIONAL        -               0.7             OK         -



------------------------

| General Dependencies |

------------------------



 error: libjpeg       libjpeg - JPEG library                                       REQUIRED        -               -               MISSING    'libjpeg needs to be installed'

 error: cups-devel    CUPS devel- Common Unix Printing System development files    REQUIRED        -               -               MISSING    'cups-devel needs to be installed'

 error: cups-image    CUPS image - CUPS image development files                    REQUIRED        -               -               MISSING    'cups-image needs to be installed'

 error: libpthread    libpthread - POSIX threads library                           REQUIRED        -               b'2.31'         MISSING    'libpthread needs to be installed'

 error: libusb        libusb - USB library                                         REQUIRED        -               1.0             MISSING    'libusb needs to be installed'

 sane                 SANE - Scanning library                                      REQUIRED        -               -               OK         -

 error: sane-devel    SANE - Scanning library development files                    REQUIRED        -               -               MISSING    'sane-devel needs to be installed'

 error: libnetsnmp-devel libnetsnmp-devel - SNMP networking library development files REQUIRED        5.0.9           -               MISSING    'libnetsnmp-devel needs to be installed'

 error: libcrypto     libcrypto - OpenSSL cryptographic library                    REQUIRED        -               1.1.1           MISSING    'libcrypto needs to be installed'

 python3X             Python 2.2 or greater - Python programming language          REQUIRED        2.2             3.8.2           OK         -

 python3-notify2      Python libnotify - Python bindings for the libnotify Desktop notifications OPTIONAL        -               -               OK         -

 error: python3-pyqt4-dbus PyQt 4 DBus - DBus Support for PyQt4                         OPTIONAL        4.0             -               MISSING    'python3-pyqt4-dbus needs to be installed'

 error: python3-pyqt4 PyQt 4- Qt interface for Python (for Qt version 4.x)         REQUIRED        4.0             -               MISSING    'python3-pyqt4 needs to be installed'

 python3-dbus         Python DBus - Python bindings for DBus                       REQUIRED        0.80.0          1.2.16          OK         -

 python3-xml          Python XML libraries                                         REQUIRED        -               2.2.9           OK         -

 error: python3-devel Python devel - Python development files                      REQUIRED        2.2             3.8.2           MISSING    'python3-devel needs to be installed'

 python3-pil          PIL - Python Imaging Library (required for commandline scanning with hp-scan) OPTIONAL        -               7.0.0           OK         -

 python3-reportlab    Reportlab - PDF library for Python                           OPTIONAL        2.0             3.5.34          OK         -



--------------

| COMPILEDEP |

--------------



 error: libtool       libtool - Library building support services                  REQUIRED        -               -               MISSING    'libtool needs to be installed'

 error: gcc           gcc - GNU Project C and C++ Compiler                         REQUIRED        -               -               MISSING    'gcc needs to be installed'

 error: make          make - GNU make utility to maintain groups of programs       REQUIRED        3.0             -               MISSING    'make needs to be installed'



---------------------

| Python Extentions |

---------------------



 cupsext              CUPS-Extension                                               REQUIRED        -               3.20.3          OK         -

 hpmudext             IO-Extension                                                 REQUIRED        -               3.20.3          OK         -



----------------------

| Scan Configuration |

----------------------



'/etc/sane.d/dll.d/hpaio' not found.

 hpaio                HPLIP-SANE-Backend                                           REQUIRED        -               3.20.3          OK         'hpaio found in /etc/sane.d/dll.conf'

 scanext              Scan-SANE-Extension                                          REQUIRED        -               3.20.3          OK         -



------------------------------

| DISCOVERED SCANNER DEVICES |

------------------------------



No Scanner found.



--------------------------

| DISCOVERED USB DEVICES |

--------------------------



No devices found.



---------------------------------

| INSTALLED CUPS PRINTER QUEUES |

---------------------------------



 

lpstat

------

Type: Unknown

Device URI: No destinations added.





--------------

| PERMISSION |

--------------



Missing Required Dependencies

-----------------------------

error: 'libcups2' package is missing or 'cups' service is not running.

error: 'libdbus-1-dev' package is missing/incompatible 

error: 'libjpeg-dev' package is missing/incompatible 

error: 'libcups2-dev' package is missing or 'cups' service is not running.

error: 'cups-bsd' package is missing or 'cups' service is not running.

error: 'cups-client' package is missing or 'cups' service is not running.

error: 'libcupsimage2-dev' package is missing or 'cups' service is not running.

error: 'build-essential' package is missing/incompatible 

error: 'libusb-1.0.0-dev' package is missing/incompatible 

error: 'libusb-0.1-4' package is missing/incompatible 

error: 'libsane-dev' package is missing/incompatible 

error: 'libsnmp-dev' package is missing/incompatible 

error: 'snmp-mibs-downloader' package is missing/incompatible 

error: 'openssl' package is missing/incompatible 

error: 'python3-pyqt4' package is missing/incompatible 

error: 'gtk2-engines-pixbuf' package is missing/incompatible 

error: 'python3-dev' package is missing/incompatible 

error: 'libtool' package is missing/incompatible 

error: 'libtool-bin' package is missing/incompatible 

error: 'build-essential' package is missing/incompatible 

error: 'build-essential' package is missing/incompatible 

Missing Optional Dependencies

-----------------------------

error: 'gtk2-engines-pixbuf' package is missing/incompatible 

error: 'xsane' package is missing/incompatible 

error: 'python3-dbus.mainloop.qt' package is missing/incompatible 





ENTER SUDO PASSWORD

-------------------

Please enter the sudoer password: 

 



Checking Permissions....





Checking for Configured Queues....

No Queue added



warning: No Queue(s) configured.





Checking for HP Properitery Plugin's....

No plug-in printers are configured.

 

Diagnose completed...







More information on Troubleshooting,How-To's and Support is available on http://hplipopensource.com/hplip-web/index.html

The first thing that seems odd is that it is reported that hplip-gui on Ubuntu 20.04 is compiled against qt5. Also many of these packages reported missing/incompatible are already installed (via apt).

Before my fresh install, I tried apt purge to get rid of everything hplip and reinstalled them, never with any success. I tried this several times and eventually somehow broke my system which lead to the fresh installation.

I am not sure what to do from here to get hplip working.