Bug#979177: cups-filters-core-drivers: Adding a printer impossible because "driverless" is too slow

[Shai Berger <shai@platonix.com>]

Package: cups-filters-core-drivers
Version: 1.28.6-1
Severity: normal

Dear Maintainer,

I've seen some misbehavior from my printer, and tried to remove and add it
back again. This failed, with the symptoms described in
https://unix.stackexchange.com/questions/276736/cups-adding-printer-fails-with-unable-to-get-list-of-printer-drivers-success
that is, no matter what interface I use -- KDE, Gnome or the web
via localhost:631 -- I get the same error when trying to find
drivers for the printer:

	Unable to get list of printer drivers:
	Success

Following the advice on that page, I tried to see if removal of
one of the files in /usr/lib/cups/driver can help me get faster
results, and I found that the guilty script was
/usr/lib/cups/driver/driverless

I then tried to run this script in isolation, and got:

$ time /usr/lib/cups/driver/disabl/driverless list
DEBUG: Started ippfind (PID 19070)
Failed to get info about driverless support.
"driverless:ipp://HP%20OfficeJet%206950%20%5B00A23E%5D%20(USB)._ipp._tcp.local/" en "HP" "HP OfficeJet 6950, driverless - cannot check driverless status, cups-filters 1.28.6" "MFG:HP;MDL:OfficeJet 6950;CMD:PCLM,PCL,PWGRaster,AppleRaster,JPEG,URF,PWG;"
"driverless-fax:ipp://HP%20OfficeJet%206950%20%5B00A23E%5D%20(USB)._ipp._tcp.local/" en "HP" "HP OfficeJet 6950, Fax, driverless - cannot check driverless status, cups-filters 1.28.6" "MFG:HP;MDL:OfficeJet 6950;CMD:PCLM,PCL,PWGRaster,AppleRaster,JPEG,URF,PWG;"
DEBUG: ippfind (PID 19070) exited with no errors.

real    3m1.817s
user    0m0.005s
sys     0m0.015s

Noticing my specific printer named in the output -- could it be
that the script tries to communicate with it, but fails to do it
in a robust way?

-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (990, 'testing'), (800, 'unstable'), (800, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.9.0-5-amd64 (SMP w/4 CPU threads)
Locale: LANG=en_IL.UTF-8, LC_CTYPE=en_IL.UTF-8 (charmap=UTF-8), LANGUAGE=en_US
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages cups-filters-core-drivers depends on:
ii  bc                 1.07.1-2+b2
ii  cups-ipp-utils     2.3.3op1-3
ii  libc6              2.31-6
ii  libcups2           2.3.3op1-3
ii  libcupsfilters1    1.28.6-1
ii  libgcc-s1          10.2.1-3
ii  liblcms2-2         2.9-4+b1
ii  libpoppler-cpp0v5  20.09.0-3
ii  libqpdf28          10.0.4-1
ii  libstdc++6         10.2.1-3
ii  poppler-utils      20.09.0-3
ii  zlib1g             1:1.2.11.dfsg-2

cups-filters-core-drivers recommends no packages.

cups-filters-core-drivers suggests no packages.

-- no debconf information