hp-setup crashes: not enough values to unpack

[bob]

I am running Fedora 32 as a non-root user. I have installed the HPLIP packages using dnf (Fedora package manager).

HPLIP fails to install a brand new Scanjet Pro N4000 snw1 that is hooked up via the USB3 cable. The Device Discovery window (Step 1 of 3) opens, USB is selected, and upon clicking next, I proceed to Step 2 of 3 where the scanner is listed as the only discovered device. I am instructed to click NEXT to continue. Clicking "next" results in a failure. The console issues the following error:

HP Linux Imaging and Printing System (ver. 3.20.11)
Printer/Fax Setup Utility ver. 9.0

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.

Searching... (bus=usb, search=(None), desc=0)
Traceback (most recent call last):
  File "/usr/share/hplip/ui5/setupdialog.py", line 1329, in NextButton_clicked
    self.showAddPrinterPage()
  File "/usr/share/hplip/ui5/setupdialog.py", line 711, in showAddPrinterPage
    self.findPrinterPPD()
  File "/usr/share/hplip/ui5/setupdialog.py", line 790, in findPrinterPPD
    self.print_ppd = cups.getPPDFile2(self.mq, self.model, self.ppds)
  File "/usr/share/hplip/prnt/cups.py", line 596, in getPPDFile2
    for f, pdl_list, driver_list in matches:
ValueError: not enough values to unpack (expected 3, got 2)

Upon displaying this message in the console, the "Next" button in the GUI changes to an "Add Printer" button. I am only given the choices of "BACK", "ADD PRINTER" or "CANCEL". Clicking Add Printer results in a core dump:

Traceback (most recent call last):
  File "/usr/share/hplip/ui5/setupdialog.py", line 1329, in NextButton_clicked
    self.showAddPrinterPage()
  File "/usr/share/hplip/ui5/setupdialog.py", line 711, in showAddPrinterPage
    self.findPrinterPPD()
  File "/usr/share/hplip/ui5/setupdialog.py", line 790, in findPrinterPPD
    self.print_ppd = cups.getPPDFile2(self.mq, self.model, self.ppds)
  File "/usr/share/hplip/prnt/cups.py", line 596, in getPPDFile2
    for f, pdl_list, driver_list in matches:
ValueError: not enough values to unpack (expected 3, got 2)
Aborted (core dumped)

Upon running hp-check -r, I am told that the following packages are missing. That error message is bogus as these package names do not exist in Fedora, so this has to be a second bug where the ubuntu versions of the packages are being checked and improper output is given:

-----------
| SUMMARY |
-----------

Missing Required Dependencies
-----------------------------
error: 'cups' package is missing or 'cups' service is not running.
error: 'avahi-devel' package is missing/incompatible

Missing Optional Dependencies
-----------------------------
None

Total Errors: 2
Total Warnings: 1

Also note that I have verified taht the cups warning is a false report. Localhost:631 in the browser allows me to adminster cups and the associated printers.

[zdohnal (zdohnal)]

Hi Bob,

there was a bug in hplip in Fedora (https://bugzilla.redhat.com/show_bug.cgi?id=1912147) which was fixed recently. F32 version still hasn't got into stable repositories because of lack of people, who would test it - https://bodhi.fedoraproject.org/updates/FEDORA-2021-a400e2d576

You can enable the testing repo when updating hplip by:

$ sudo dnf --enablerepo=updates-testing upgrade hplip

and, if it works, please add the karma to the update.

If it doesn't, please file a new bugzilla at bugzilla.redhat.com.

Thank you in advance!

[bob (coralnut)]

Thanks for the prompt response.
I regret that the updated fix in the testing repo doesn't solve the problem, because what I am reporting is a different bug.

Bug report filed on fedora:
https://bugzilla.redhat.com/show_bug.cgi?id=1927149