Some python packages could not be installed during hplip-3.20.5 installing on Ubuntu 20.04

In fact there is some troubles using hplip-3.20.6 on Ubuntu 20.04. The installation complains about pyqt5. My workaround is to install hplib-3.20.6 with the custom option (instead of automatic). You can install hplib without qt support (without: Graphical User Interfaces (Qt5)). In a terminal please run:

./hplip-3.20.6.run

Now you can select the custom installation and disable qt5:

Do you wish to enable 'Graphical User Interfaces (Qt5)' (y=yes*, n=no, q=quit) ? n

You get:

INSTALLATION MODE
-----------------
Automatic mode will install the full HPLIP solution with the most common options.
Custom mode allows you to choose installation options to fit specific requirements.

Please choose the installation mode (a=automatic*, c=custom, q=quit) : c


INTRODUCTION
------------
This installer will install HPLIP version 3.20.6 on your computer.
Please close any running package management systems now (YaST, Adept, Synaptic, Up2date, etc).


DISTRO/OS CONFIRMATION
----------------------
Distro appears to be Ubuntu 20.04.

Is "Ubuntu 20.04" your correct distro/OS and version (y=yes*, n=no, q=quit) ? y


DRIVER OPTIONS
--------------
Would you like to install Custom Discrete Drivers or Class Drivers ( 'd'= Discrete Drivers*,'c'= Class Drivers,'q'= Quit)?   : d

Initializing. Please wait...


SELECT HPLIP OPTIONS
--------------------
You can select which HPLIP options to enable. Some options require extra dependencies.

Do you wish to enable 'Network/JetDirect I/O' (y=yes*, n=no, q=quit) ? y
Do you wish to enable 'Graphical User Interfaces (Qt5)' (y=yes*, n=no, q=quit) ? n
Do you wish to enable 'PC Send Fax support' (y=yes*, n=no, q=quit) ? y
Do you wish to enable 'Scanning support' (y=yes*, n=no, q=quit) ? y
Do you wish to enable 'HPLIP documentation (HTML)' (y=yes*, n=no, q=quit) ? y

I hope this comment will be usefull, Regards.

There is a solution, it took a while. I have just compiled hplip 3.20.9 with Qt5. And used below discussion hint to solve python-PyQt5 missing dependency: https://answers.launchpad.net/hplip/+question/691141 Seems now printers start working with Ubuntu 20.04.

    HP Linux Imaging and Printing System (ver. 3.20.9)
    Dependency/Version Check Utility ver. 15.1

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.

Note: hp-check can be run in three modes:
1. Compile-time check mode (-c or --compile): Use this mode before compiling the HPLIP supplied tarball (.tar.gz or .run) to determine if the proper dependencies are installed to successfully compile HPLIP.                                
2. Run-time check mode (-r or --run): Use this mode to determine if a distro supplied package (.deb, .rpm, etc) or an already built HPLIP supplied tarball has the proper dependencies installed to successfully run.                         
3. Both compile- and run-time check mode (-b or --both) (Default): This mode will check both of the above cases (both compile- and run-time dependencies).                                                                                    

Check types:                                                                                                                                                                                                                                  
a. EXTERNALDEP - External Dependencies                                                                                                                                                                                                        
b. GENERALDEP - General Dependencies (required both at compile and run time)                                                                                                                                                                  
c. COMPILEDEP - Compile time Dependencies                                                                                                                                                                                                     
d. [All are run-time checks]                                                                                                                                                                                                                  
PYEXT SCANCONF QUEUES PERMISSION                                                                                                                                                                                                              

Status Types:
    OK
    MISSING       - Missing Dependency or Permission or Plug-in
    INCOMPAT      - Incompatible dependency-version or Plugin-version

 
---------------
| SYSTEM INFO |
---------------

 Kernel: 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 GNU/Linux
 Host: Kodibuntu
 Proc: 5.4.0-48-generic #52-Ubuntu SMP Thu Sep 10 10:58:49 UTC 2020 GNU/Linux
 Distribution: 12 20.04
 Bitness: 64 bit


-----------------------
| HPLIP CONFIGURATION |
-----------------------

HPLIP-Version: HPLIP 3.20.9
HPLIP-Home: /usr/share/hplip
HPLIP-Installation: Auto installation is 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=3.20.9

[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.20.9
html=/usr/share/doc/hplip-3.20.9
icon=/usr/share/applications
cupsbackend=/usr/lib/cups/backend
cupsfilter=/usr/lib/cups/filter
drv=/usr/share/cups/drv/hp
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=no
foomatic-drv-install=no
foomatic-ppd-install=no
foomatic-rip-hplip-install=no
hpcups-install=yes
cups-drv-install=yes
cups-ppd-install=no
internal-tag=3.20.9
restricted-build=no
ui-toolkit=qt5
qt3=no
qt4=no
qt5=yes
policy-kit=no
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:
Plugins are not installed. Could not access file: No such file or directory

Current contents of '~/.hplip/hplip.conf' file:
[upgrade]
notify_upgrade = false
last_upgraded_time = 1518909741
pending_upgrade_time = 0
latest_available_version = 3.17.10

[settings]
systray_visible = 0
systray_messages = 0

[last_used]
device_uri = hp:/usb/Photosmart_7400_series?serial=CN53C2Z1HKUJ
printer_name = Photosmart_7400
working_dir = .

[commands]
scan = /usr/bin/xsane -V %SANE_URI%

[refresh]
rate = 30
enable = false
type = 1

[polling]
enable = false
interval = 5
device_list = 

[fax]
voice_phone = 
email_address = 

[installation]
date_time = 10/06/20 02:33:45
version = 3.20.9


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

-------------------------
| External Dependencies |
-------------------------

 cups                 CUPS - Common Unix Printing System                           REQUIRED        1.1             2.3.1           OK         'CUPS Scheduler is running'
 gs                   GhostScript - PostScript and PDF language interpreter and previewer REQUIRED        7.05            9.50            OK         -
 xsane                xsane - Graphical scanner frontend for SANE                  OPTIONAL        0.9             0.999           OK         -
 scanimage            scanimage - Shell scanning program                           OPTIONAL        1.0             1.0.29          OK         -
 dbus                 DBus - Message bus system                                    REQUIRED        -               1.12.16         OK         -
 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 |
------------------------

 libjpeg              libjpeg - JPEG library                                       REQUIRED        -               -               OK         -
 cups-devel           CUPS devel- Common Unix Printing System development files    REQUIRED        -               2.3.1           OK         -
 cups-image           CUPS image - CUPS image development files                    REQUIRED        -               2.3.1           OK         -
 libpthread           libpthread - POSIX threads library                           REQUIRED        -               b'2.31'         OK         -
 libusb               libusb - USB library                                         REQUIRED        -               1.0             OK         -
 sane                 SANE - Scanning library                                      REQUIRED        -               -               OK         -
 sane-devel           SANE - Scanning library development files                    REQUIRED        -               -               OK         -
 libavahi-dev         libavahi-dev                                                 REQUIRED        -               -               OK         -
 libnetsnmp-devel     libnetsnmp-devel - SNMP networking library development files REQUIRED        5.0.9           5.8             OK         -
 libcrypto            libcrypto - OpenSSL cryptographic library                    REQUIRED        -               1.1.1           OK         -
 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         -
 python3-pyqt5-dbus   PyQt 5 DBus - DBus Support for PyQt5                         OPTIONAL        5.0             5.14.1          OK         -
 python3-pyqt5        PyQt 5- Qt interface for Python (for Qt version 4.x)         REQUIRED        5.0             5.14.1          OK         -
 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         -
 python3-devel        Python devel - Python development files                      REQUIRED        2.2             3.8.2           OK         -
 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 |
--------------

 libtool              libtool - Library building support services                  REQUIRED        -               2.4.6           OK         -
 gcc                  gcc - GNU Project C and C++ Compiler                         REQUIRED        -               9.3.0           OK         -
 make                 make - GNU make utility to maintain groups of programs       REQUIRED        3.0             4.2.1           OK         -

---------------------
| Python Extentions |
---------------------

 cupsext              CUPS-Extension                                               REQUIRED        -               3.20.9          OK         -
 hpmudext             IO-Extension                                                 REQUIRED        -               3.20.9          OK         -

----------------------
| Scan Configuration |
----------------------

 hpaio                HPLIP-SANE-Backend                                           REQUIRED        -               3.20.9          OK         'hpaio found in /etc/sane.d/dll.conf'
 scanext              Scan-SANE-Extension                                          REQUIRED        -               3.20.9          OK         -

Try installing pyqt5 with pip:

sudo apt install python-pip
pip install pyqt5
pip install pyqt5.sip

or if your version of hplip requires python3:

sudo apt install python3-pip
pip3 install pyqt5
pip3 install pyqt5.sip

Still an issue even with <=hplip-3.21.10.

It tries to install python2 packages, even though your 20.04 Ubuntu has python3 as the default.

To fix install this helper package:

sudo apt install python-is-python3

It will pretend to the hplip installer to use python3 instead of python2.

To summarize a solution previously alluded to (from Bartosz), what worked for me was to basically change the python symlink in /usr/bin to point to Python 3 instead of Python 2, as described in one of the answers at https://answers.launchpad.net/hplip/+question/691141.

cd /usr/bin
sudo unlink python
sudo ln -s /usr/bin/python3 python

I've been experienced this issue and also very struggle to find the solution because the problem seems I haven't installed pyqt5 but it's already installed (using python3) borrowed from this gist

pip3 install --user pyqt5  
sudo apt-get install python3-pyqt5  
sudo apt-get install pyqt5-dev-tools
sudo apt-get install qttools5-dev-tools

Finally, I found a website describing HPLIP problem on ubuntu exactly as I had at here https://ubuntuhandbook.org/index.php/2021/07/install-latest-hplip-ubuntu-20-04-fix/

The problem is because by default HPLIP installer using python at /usr/bin/python and that refers to python2.7 which is unrelated with the installed pyqt5 at my python3

So based on that site, I choose to use update-alternatives to switch python version to python3 when the installer using /usr/bin/python

sudo update-alternatives --install /usr/bin/python python /usr/bin/python2 1
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 2

the first command is to add python2 at option number 1, and the second one is to add python3 at option number 2.

Here's the screenshot of when I switch to python3 and python2, before starting the installation again using python3 as the default one

It seems Ubuntu 20.04 is not supported by hplip 3.20.5 and below hplip releases. At least, Ubuntu 20.04 has not been mentioned on hp's Developer Portal | Release Notes page. The last mentioned Ubuntu version is 19.10 at the time.

So the optimal solution in my case is to wait for newer hplip release and use 18.04 VM on VirtualBox with USB 1.1 passthrough enabled for my hp 1020 printer until newer hplip released.

I don't know how, but maybe some update for 3.20.3 has resolved the issue with printing on 20.04

$ cat /var/log/dpkg.log | grep hplip
2020-08-07 15:29:39 status installed hplip-gui:all 3.20.3+dfsg0-2
2020-08-07 15:29:39 remove hplip-gui:all 3.20.3+dfsg0-2 <none>
2020-08-07 15:29:39 status half-configured hplip-gui:all 3.20.3+dfsg0-2
2020-08-07 15:29:39 status half-installed hplip-gui:all 3.20.3+dfsg0-2
2020-08-07 15:29:39 status config-files hplip-gui:all 3.20.3+dfsg0-2
2020-08-07 15:29:39 status installed hplip:amd64 3.20.3+dfsg0-2
2020-08-07 15:29:39 remove hplip:amd64 3.20.3+dfsg0-2 <none>
2020-08-07 15:29:39 status half-configured hplip:amd64 3.20.3+dfsg0-2
2020-08-07 15:29:39 status half-installed hplip:amd64 3.20.3+dfsg0-2
2020-08-07 15:29:39 status config-files hplip:amd64 3.20.3+dfsg0-2

After connecting printer dialogue window appeared and said that plugin is required for it and proposed a few options. I've left the default and installed proposed plugin. After the installation I was able to print using HP LJ 1020 from Ubuntu 20.04

$ dpkg --list | grep hplip
ii  hplip             3.20.3+dfsg0-2      amd64     HP Linux Printing and Imaging System (HPLIP)
ii  hplip-data        3.20.3+dfsg0-2      all       HP Linux Printing and Imaging - data files
ii  hplip-doc         3.20.3+dfsg0-2      all       HP Linux Printing and Imaging - documentation
ii  hplip-gui         3.20.3+dfsg0-2      all       HP Linux Printing and Imaging - GUI utilities (Qt-based)

It works in spite of hp-check outputs:

Missing Required Dependencies
-----------------------------
error: 'libcups2' package is missing/incompatible 
error: 'python3-pyqt4' package is missing/incompatible 
error: 'gtk2-engines-pixbuf' package is missing/incompatible 

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

Total Errors: 3

1st and 3rd packages are installed, so they are incompatible, 2nd and 4th packages are not available from official Ubuntu repositories. It could impact some functionality. But I'm glad it prints at least.

As none of the solutions provided up to 2021-02-15 solved this issue for my specific case (i.e. 64-bit XUbuntu 20.04.3 LTS with kernel 5.13.0-28-generic + wireless HP Deskjet Ink Advantage 2546 a.k.a. "Deskjet 2540 series" all-in-one printer), I ended up running the following shell terminal commands, which then solved the issue for me:

1. Purge the current HPLIP installation:

   sudo apt-get purge hplip* -y
   

2. Install a DEB package that makes any application-level reference to python point to the system-default (i.e. *Ubuntu 20.04's default) python 3 installation:

   sudo apt install python-is-python3 -y
   

3. Install the HPLIP packages that ship with *Ubuntu (i.e. Ubuntu, KUbuntu, XUbuntu...) 20.04:

   sudo apt install hplip hplip-data hplip-gui -y
   

4. Access the current user's Downloads folder:

   cd ~/Downloads
   

5. Download HPLIP version 3.21.12 (released 2021-12-16) as a .run (i.e. shell script) installation file and store it in such user's Downloads folder:

   wget https://sourceforge.net/projects/hplip/files/hplip/3.21.12/hplip-3.21.12.run/download -O ./hplip-3.21.12.run
   

6. Make such downloaded script executable:

   chmod +x ./hplip-3.21.12.run
   

7. Run the installation script:

   ./hplip-3.21.12.run
   

8. Durig the installation procedure, press Enter (return) in order to apply all default (*) options. If you are asked if you wish to remove (uninstall) the current HPLIP install and then install the HPLIP from the script, select such option (i) instead of the quit option.

9. Confirm that you want to download and install the HPLIP plugin (or re-plug in if the plugin is already installed). Be patient: it takes a while to download and install the plugin. You may think that the plugin installer's window is static because nothing is happening, but looking at the terminal window it's noticeable that the installer is contacting the web server, downloading and then installing the plugin.

10. Reboot / restart the computer (you may ether press r and confirm once the installer asks if you wish to restart, or you may alternatively finish the installation, close all windows and only then reboot, manually).

After you turn your HP printer on, if the plugin at the panel does nothing after you click on it and then click on HP Device Manager, click on the applications menu, type hp device manager and select it so you can add and then configure your HP printer. You may also run HP Device Manager from the terminal by issuing this command:

hp-toolbox & exit