Thunderbird (52.8.0) shows non-existant printers?

Hi,

Everywhere I look, CUPS, HP-SysTray, LibreOffice Apps, I see the printers that I expect to see.

However, in Thunderbird, I see these PLUS some non-existent printers.

These were on the system in the past, so are not spontaneous creations. But they should not be listed anymore.
If the names were not so close to working printers, I’d be tempted to ignore them.
Unfortunately if I do accidentally select a phantom printer I’m stuck with only a reset as the way out!!
Where is Thunderbird looking to find these “dead” printers?

Regards, Martin

Not avahi printers being advertised on the network? Some CUPS host advertising them?

Check with

avahi-browse -alrt

If so, that behaviour can be inhibited if desired.

Hello again Deano,

Yep! You’re spot on… Thanks.
How would you suggest I could inhibit seeing these network printers?

What puzzles me is that both displayed objects are the same printer?
For example, an HP 8600 Printer/Scanner (at 192.168.x.y) has IPP printing enabled.
The tablets (Android & Apple - don’t know the details of how?) see and use this single printer quite happily.
The majority of Leap 15 applications (Thunderbird is the exception) see the same CUPS printer at ipp://myHP8600.localnet:631/ipp/printer.
While Thunderbird sees two printers at that address?
One (ipp://myHP8600.local:631/ipp/printer) will work, the other, will not?

http://paste.opensuse.org/36113151

Regards, Martin
PS - Hope the image works?

This the same as above, but I hope the image works this time (How should I include image & how do I edit these posts?)

Hello again Deano,

Yep! You’re spot on… Thanks.
How would you suggest I could inhibit seeing these network printers?

What puzzles me is that both displayed objects are the same printer?
For example, an HP 8600 Printer/Scanner (at 192.168.x.y) has IPP printing enabled.
The tablets (Android & Apple - don’t know the details of how?) see and use this single printer quite happily.
The majority of Leap 15 applications (Thunderbird is the exception) see the same CUPS printer at ipp://myHP8600.localnet:631/ipp/printer.
While Thunderbird sees two printers at that address?
One (ipp://myHP8600.local:631/ipp/printer) will work, the other, will not?

http://paste.opensuse.org/36113151

Regards, Martin

If you don’t need avahi running, you can disable and mask avahi.socket and avahi.service (for permanent effect)…

sudo systemctl stop avahi-daemon.socket avahi-daemon.service
sudo systemctl mask avahi-daemon.socket avahi-daemon.service

and stop the avahi.service…

sudo systemctl stop avahi-daemon.service

What puzzles me is that both displayed objects are the same printer?
For example, an HP 8600 Printer/Scanner (at 192.168.x.y) has IPP printing enabled.
The tablets (Android & Apple - don’t know the details of how?) see and use this single printer quite happily.
The majority of Leap 15 applications (Thunderbird is the exception) see the same CUPS printer at ipp://myHP8600.localnet:631/ipp/printer.
While Thunderbird sees two printers at that address?
One (ipp://myHP8600.local:631/ipp/printer) will work, the other, will not?

I’ve seen this reported elsewhere some time ago. I think that might happen if you also have cups-browsed active. Then CUPS will also enumerate the discovered printer(s). You can check with…

systemctl status cups-browsed

I know you will think this a silly question! But how do I know if I need avahi or not?
I would be happy to turn off Thunderbird’s use of avahi but system wide? That is a bit extreme.
Maybe an option for you Super Users but my gut feeling is that if I did that, it will come back and bite me on the bum!
I think I’ll just change the description in the IPP Server to “Do Not Use In Thunderbird!”

I guess that this means that cups-browsed is not running?

linux-g1sl:~ # systemctl status cups-browsed
● cups-browsed.service - Make remote CUPS printers available locally
   Loaded: loaded (/usr/lib/systemd/system/cups-browsed.service; disabled; vendor preset: disabled)
   Active: inactive (dead)
linux-g1sl:~ # 

Once again, thank you for all your help, Martin

I actually do use it from time to time, sine I often have a few hosts on a LAN and it is a great way to reach them by <hostname>.local when the need arises. CUPS also can make use of it for network printer discovery, but most users would not be affected disabling it completely.[/QUOTE]

I would be happy to turn off Thunderbird’s use of avahi but system wide? That is a bit extreme.

It may not be a suitable solution for all users (depending on their need for avahi), but I don’t think most users would miss it.

I guess that this means that cups-browsed is not running?

linux-g1sl:~ # systemctl status cups-browsed
● cups-browsed.service - Make remote CUPS printers available locally
   Loaded: loaded (/usr/lib/systemd/system/cups-browsed.service; disabled; vendor preset: disabled)
   Active: inactive (dead)
linux-g1sl:~ # 

Once again, thank you for all your help, Martin

Yes, that means it’s not active, but I see now that you had a CUPS defined printer as well as the ‘avahi-discovered’ printer. Glad to have been of some assistance.

FWIW, I managed to locate a thread I had read previously discussing this very subject
http://debian.2.n7.nabble.com/How-to-Turn-Off-Autodiscovered-Printers-in-Firefox-td4196559.html

None of the workarounds are ideal, and it arises because the CUPS client libraries get the list of discovered printers directly from avahi, rather than just from CUPS (which I think is a big mistake)…

The cups client libraries now also get a list of network printers from Avahi.
In older versions of cups, this was only done by the cups server.

This is now done in the client-side cups libraries (ie libcups.so,
which GNOME and KDE apps link against) and not in the cupsd server.
So changing the “Browse” settings in the cups server won’t work.

$ ldd /usr/lib/x86_64-linux-gnu/libcups.so.2

libavahi-common.so.3 => /usr/lib/x86_64-linux-gnu/libavahi-common.so.3
libavahi-client.so.3 => /usr/lib/x86_64-linux-gnu/libavahi-client.so.3

IE this behaviour (of showing remote printers in the Print dialog box) happens
even if you turn off your local cups server. You can disable it by turning off
the avahi service, but that will disable all zeroconf/mdns related
functionality.

One workaround mentioned was as follows…

However, there is at least a way to turn off most of avahi’s functionality
(including adding remote printers into the CUPS clients) while keeping the DNS
functionality (eg when looking up foo.local-style host names):
edit /etc/avahi/avahi-daemon.conf and in the [server] section, add
enable-dbus=no then restart the avahi-daemon service.

The main issue with doing that is any time a user wants to print via an application, there will be a significant delay before the print dialogue comes up. It might still be a workable solution for some users though.

Actually, disabling avhi dbus communication does horrible things (lockups) with KDE applications when trying to print, so not advised. However, at least KDE apps don’t list these avahi-reported printers.