Desktop Team Updates - Monday 27th September 2021

Hi everyone, below you will find the updates from the Desktop team from the last week. If you’re interested in discussing a topic please start a thread in the Desktop area of Discourse .

Last week’s notes are here: Desktop Team Updates - Monday 20th September 2021

  • WSL
    • Packaging of ubuntu-wsl-setup as a snap.

Ubuntu Desktop Installer

WSL Setup Wizard

Subiquity client


  • WSL
    • Packaging of ubuntu-wsl-setup as a snap. Many fixes alongside (ubuntu-desktop-installer, subiquity…)
    • PR reviews
  • Impish
    • uploaded the default launcher config update for the firefox snap from Olivier
    • updated ubiquity-slideshow-ubuntu slides for the new artwork
    • GNOME stable updates
  • New desktop installer
    • reviewed the livecd build changes to include locales information in the catalogs
    • debugged a segfault on missing icons which turned out to be a classic snap problem. We use gdk-pixbuf from the snap but read the cache from the system which doesn’t include the png loader anymore since that’s builtin in newer versions. Proposed a fix with a launcher script copied for the gnome one.
    • confirmed that the casper mount hack we needed for the canary image isn’t needed anymore
    • tried a casper change to ‘chgrp adm /var/log/installer’, otherwise the fronted doesn’t have enough rights to write its log
    • tested the minimal installation option now that it has a backend and confirmed that it is working
  • Others
    • update the thunderbird beta snap to 92.0b3
    • beta ISO testing
    • launchpad bug triaging

firefox24 firefox

thunderbird24 thunderbird

  • prepared 91.1.1 update
  • removed block-proposed tag to get 91 in impish for wider field testing

chromium22 chromium

  • updated beta then stable to 94.0.4606.54
  • updated dev to 95.0.4638.17

flutter24 Ubuntu Desktop Installer

package24 other



  • Fixed gnome-session (and ubuntu one) to support Wayland login on nvidia [MR]
  • Some cleanups on GWeakRef’s threading races fixes on GObjec [MR, finally merged]
  • Some more rebasing / cleaups on the eprivacy branch for mutter
  • Fixed an issue causing icons not being updated on GNOME Shell [MR]
  • Various upstream reviews, including signal manager on g-s [MR].
  • Politics: various discussions with Yaru team and Upstream regarding libadwaita and vendor styles.
  • Some indicators extension fixes [commits]



Add optional support to libfuse3 to open-vm-tools [PR]

  • CUPS Snap: Waiting for @ijohnson’s pull request on snapd for the cups printing interface to get merged by the snapd team (ETA: October).
  • cups-filters: Several bug fixes, in addition to minor fixes especially also ones related to the CUPS-driver-retro-fitting Printer Applications, here Gutenprint: Fixed PPD URIs when generating dynamic PPDs (commit), deal with too large custom page size limits in PPD files (commit).
  • HPLIP Printer Application: Switched from HP’s original HPLIP source code to the source code of the Debian package which includes 81 patches fixing several bugs which got reported to HP buy not addressed. Thanks to Thorsten Alteholz to update the HPLIP package in Debian unstable.
  • Gutenprint Printer Application: Also retro-fitted the Gutenprint CUPS driver into a Printer Application and posted in the Snap Store. Snap needs patching of PAPPL to support 256 instead of only 32 vendor options. Discussed the design of a native GutenPrint Printer Application on the Gutenprint mailing list. Michael Sweet (author of PAPPL) is defending the strict limitation of the number of vendor-specific options which Robert Krawitz (upstream maintainer of Gutenprint) is defending the need of the vast range of user-adjustable parameters to get best print quality and flexibility (including 3rd-party ink sets).
  • pappl-retrofit: Extended API to easily add extra buttons and pages to the web interface, so that one can add things like a page to download the proprietary HPLIP plugin, or clean/align print heads on inkjet printers. Also did some improvements on driver data generation from the PPD and fixed some bugs.
  • All Printer Applications: In the Snaps patched PAPPL to allow 256 instead of only 32 vendor-specific options, de-activate log rotation (does not work with the forking filter functions), and default logging to “error” instead of “debug” (can be easily changed in web interface) to not fill up disk without log rotation, and use always CUPS’ backends instead of PAPPL’s. as they better work together with the CUPS drivers, use CUPS’ collection of hundreds of USB quirk workarounds, and configurability of SNMP backend and USB quirks.
  • ipp-usb Snap: Started investigations about how to use UDEV from inside a Snap.
  • pdfio: Posted 2 feature requests on Michael Sweet’s non-C++ PDF handling library, in order to replace QPDF in cups-filters in the future: Support for flattening filled PDF forms and streaming PDF/PCLm output. The latter Mike has already implemented!
  • Linux Plumbers Conference 2021: The OpenPrinting Micro-Conference has taken place and we have a recording on YouTube now. I, Michael Sweet (author of CUPS), Zdenek Dohnal (RedHat/Fedora printing maintainer), Thorsten Alteholz (Debian printing maintainer), Bhavna Kosta (GSoC student on scanning support in PAPPL) had a fruitful discussion about several printing-related aspects, like for example upstream development of CUPS including roadmap/schedules (CUPS 2.4 in 22.04 LTS, CUPS 3.0 in 24.04 LTS). Mike’s non-C++ pdfio instead of QPDF in cups-filters, printer setup tools for the New Architecture, Bhavna spoke about her work on scanning in PAPPL.
  • Bugs.