TurboPrint & PrintFab

Is there a trick to getting Turboprint to work on Fedora 40? I can add printers in Turboprint, but it does not seem to add them successfully to cups. The printers are not listed the next time that I open Turboprint. The "test connection" works, but the test page fails. This is all shown in the log snippet below:

root@sultan:~# grep -e cups -e turbo /var/log/messages

Oct 4 07:42:01 sultan turboprint[7601]: Failed to load module "pk-gtk-module"
Oct 4 07:42:01 sultan systemd[2351]: Started app-gnome-turboprint\x2dcontrol-7601.scope - Application launched by gnome-shell.
Oct 4 07:42:20 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST / HTTP/1.1" 426 116 CUPS-Get-Devices successful-ok
Oct 4 07:42:20 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST / HTTP/1.1" 401 116 CUPS-Get-Devices successful-ok
Oct 4 07:42:20 sultan turboprint-control.desktop[7601]: ERROR:
Oct 4 07:42:20 sultan turboprint-control.desktop[7601]: cups::enum_printers: cups-get-devices failed
Oct 4 07:42:55 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST /admin/ HTTP/1.1" 401 0 - -
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: ERROR:
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: cups::add_or_modify_printer: no response of CUPS_ADD_PRINTER request
Oct 4 07:42:55 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST /admin/ HTTP/1.1" 401 0 - -
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: ERROR:
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: cups::add_or_modify_printer: no response of CUPS_ADD_PRINTER request
Oct 4 07:42:55 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST /admin/ HTTP/1.1" 401 0 - -
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: ERROR:
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: cups::add_or_modify_printer: CUPS_ADD_PRINTER set 'device-uri' failed
Oct 4 07:42:55 sultan turboprint-control.desktop[7601]: Could not get a free pipe
Oct 4 07:42:56 sultan turboprint-control.desktop[7601]: lp -t 'TurboPrint Testpage' -d ET8550-TurboPrint /tmp/tp7601_1.tmp
Oct 4 07:42:57 sultan turboprint-control.desktop[7738]: lp: Error - The printer or class does not exist.
Oct 4 07:43:11 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST / HTTP/1.1" 200 152 Cancel-Subscription successful-ok
Oct 4 07:43:11 sultan cupsd[1842]: REQUEST 192.168.0.247 - - "POST / HTTP/1.1" 200 152 Cancel-Subscription client-error-not-found

selinux is set to permissive. Other computers access this cups server, so it is not likely a firewall issue.

cups says "CUPS-Get-Devices successful-ok", but turboprint says "cups::enum_printers: cups-get-devices failed".

So... what am I missing?

Hello, no general problem is known with TurboPrint on Fedora 40. Do you use the current TurboPrint version 2.57?

Yes, I was trying the latest download (from last week). I have not used it before.