firefox, chromium and other snap apps can't print

[Greg Mitchell]

Snap packages aren't seeing any cups printers (tried firefox and chromium snap). Native packages see printers.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: snapd 2.55.2+22.04.1
ProcVersionSignature: Ubuntu 5.15.0-23.23-generic 5.15.27
Uname: Linux 5.15.0-23-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu80
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Apr 4 14:49:58 2022
InstallationDate: Installed on 2022-03-14 (21 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Alpha amd64 (20220313)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Snap.Changes:
 ID Status Spawn Ready Summary
 19 Done 2022-04-04T12:25:24-04:00 2022-04-04T12:25:34-04:00 Auto-refresh snap "snapd"
 20 Done 2022-04-04T12:27:47-04:00 2022-04-04T12:27:47-04:00 Connect firefox:cups-control to snapd:cups-control
SourcePackage: snapd
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

Thank you for your bug report, could you add your 'journalctl -b 0 > log' to the bug after trying to print?

Also could you share the output of
$ dpkg -l | grep xdg-desktop-portal

[Greg Mitchell (greg-mitchell)]

journalctl -b 0

[Greg Mitchell (greg-mitchell)]

$ dpkg -l | grep xdg-desktop-portal
ii xdg-desktop-portal 1.14.1-2 amd64 desktop integration portal for Flatpak and Snap
ii xdg-desktop-portal-gnome 42.0.1-1 amd64 GNOME portal backend for xdg-desktop-portal
ii xdg-desktop-portal-gtk 1.14.0-1build1 amd64 GTK+/GNOME portal backend for xdg-desktop-portal

[Alberto Mardegan (mardy)]

Just yesterday we landed a fix in snapd to address some issues with cups: https://github.com/snapcore/snapd/pull/11616

Unfortunately I do not know the details of the issue that this change solves, but maybe someone with more knowledge of cups can tell if that change could fix this bug too.

[Sebastien Bacher (seb128)]

The log has

CUPS: Error getting default printer: Bad file descriptor

unsure if that's the issue, and maybe the snapd fix mentioned is needed?

[Sebastien Bacher (seb128)]

Indeed, I confirmed the issue and the fix by doing a

$ sudo snap refresh --edge snapd

restarting the machine and trying to print again the printer are listed again (note that if you try that you might want to refresh back to --stable later on otherwise you will track unstable snapd builds)