[Pkg-utopia-maintainers] Bug#846381: avahi-daemon: cups frequently forgets about all printers untils restarting avahi-daemon

[Helmut Grohne]

Control: tags -1 - moreinfo

On Mon, Jan 01, 2018 at 12:46:47AM +0000, Brian Potkin wrote:
> Thanks you for your report, Helmut.

Thanks for looking into this.

> On Wed 30 Nov 2016 at 20:57:01 +0100, Helmut Grohne wrote:
> > Since Debian jessie, cups uses avahi to broadcast its printers to the
> > local network. I have a jessie cups with a few printers and publish them
> > via avahi. Now I am seeing a little weird behaviour on client systems:
> > After booting their cups daemons know about the broadcasted printers,
> > but after some time (usually a few times a day) they forget. I have no
> 
> What are the symptoms?  How do you know that the printing system does
> not see the remote broadcasted printers on the clients?

When printers are broadcasted, client cups systems create
/etc/cups/ppd/<something>.ppd for each remote printer. These files exist
after booting and then vanish. Another way to diagnose the presence of
the issue is running "lpstat -a". After boot, it lists all the printers,
but after a while, the output becomes "lpstat: No destinations added."
When I try to print something (e.g. using evince), I am presented with
an empty printer list. Then I restart avahi-daemon on the client system
and the files are back and "lpstat -a" gives a printer list again until
it forgets again.

> First things first. Are you still experiencing this behaviour on an
> up-to-date unstable/testing system?

Yes. I see this behaviour on stretch and sid.

Is there anything else I can check? Maybe trace something? Turn on some
debug logging somewhere? The issue is sufficiently annoying that I am
willing to put some time into it.

Helmut