Xorg will be the default in 18.04 LTS

Cross posted from Insights.

Bionic Beaver, the codename for the next Ubuntu LTS release, is due in April 2018 and will ship with both the traditional Xorg graphics stack as well as the newer Wayland based stack, but Xorg will be the default.

17.10, released in October 2017, ships with the Wayland based graphics server as the default and the Xorg based equivalent is available as an option from the login screen. When we started out on the GNOME Shell route for 17.10 (Artful Aardvark) we knew that we needed to have Wayland as the default option otherwise we wouldn’t know if it would work well for our users in the LTS only 6 months later. The LTS is supported for five years meaning that we need to be certain that what goes out the door on release day will be maintainable and sustainable for the duration and will serve all our users and customers needs, which is no mean feat.

As we are roughly half way through the Bionic development cycle, the time was right for us to review that decision and make a call on whether or not Wayland is the right default display server for Bionic. We have decided that we will ship Xorg by default, and that Wayland will be an optional session available from the login screen.

Why opt for Xorg by default? There are three main reasons:

  1. Screen sharing in software like WebRTC services, Google Hangouts, Skype, etc works well under Xorg.
  2. Remote Desktop control for example RDP & VNC works well under Xorg.
  3. Recoverability from Shell crashes is less dramatic under Xorg.

The first two are closely linked. Wayland & GNOME Shell have a good plan in PipeWire and a Wayland protocol to provide a screen sharing service. This will take some more time to develop and there will be some lag while application developers include support in their services. Until that happens, Xorg is necessary for people who need screen sharing features. If you don’t need screen sharing features and prefer a more secure environment then the Wayland session is available for you, pre-installed.

The third point is about what happens when things go wrong. The architecture of GNOME Shell and Mutter is such that a GNOME Shell crash will end your whole session, killing running applications and returning you to the login screen. When using Xorg, the shell can restart independently of the display server and running applications. This means that once the shell is restarted, you can pretty much pick up your session from where you left off, with your applications still running.
There are two solutions to this problem when using Wayland: make sure the shell doesn’t crash or change the architecture. Both of these are work in progress and we continue to contribute to this work upstream. GNOME Shell 4 will bring a new architecture where there will be more flexibility in components restarting without affecting other components. But in short, we remain committed to GNOME and the GNOME stack and will continue to actively contribute to Wayland by adding features and fixing bugs.

The Wayland session will still be available, pre-installed, for people to use, but for our ‘out of the box’ users the Ubuntu experience needs to be stable and provide the features they have come to expect and use in daily life and Xorg is the best choice here, at least for 18.04 LTS, but for 18.10 we will re-evaluate Wayland as the default.


:open_mouth: didn’t know that was coming soon.

This is an excellent decision though, it’s cool that Wayland was trialled as a default but it’s still somewhat lacking so a great decision to put off the default for this LTS :slight_smile:

Good decision! Apart from the issues Will mentioned, there are also a number of papercut-type bugs on Wayland that annoy me, such as shortcuts not working correctly, and some snaps crashing.

Will there be an organized effort to get people running and testing Wayland and finding and fixing papercut-type bugs?


Not soon…
There’s some discussion going on though https://wiki.gnome.org/Initiatives/Wayland/GnomeShell/GnomeShell4

What’s coming soon, and we intend to contribute to, is the ability of splitting components, so that compositor and shell are in different parts and if the shell crashes it won’t bring down the whole desktop (and apps).


Great choice, it (18.04) being the next LTS it makes 100% sense.

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Well then, maybe its better to move back to Unity 7? It doesn’t need to use Wayland? I don’t have any problems with my Bionic Unity.

@willcooke, for those of us who are already using the development version of Bionic, will the switch from Wayland to Xorg be automatic?

Great decision for an LTS release. Wayland as it stands right now would have made a lot of things very hard or impossible for a lot of users.


What does this exactly mean? How to make sure the shell doesn’t crash? How then, change the architecture?

Perfect decision. Wayland is so clumsy.

So much for DisplayLink’s motivation to get a Wayland-compatible driver out.

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10 years I’m listening about display servers, compositors, protocols and x and wayland and mir and mutter and all this stuff. Linux desktop can really suck the life out of people sometimes.

I assume as a one off right? Ubuntu 18.04 to use X again since it’s an LTS and then 18.10 back to Wayland to continue pushing that technology forward?

Last sentence in the OP. Update This was directed at @FelicianoTech. (Thought I had hit the ‘reply’ button, guess not).

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Excellent decision! It frees the Wayland team from the pressure of meeting the LTS schedule.

The architecture of GNOME Shell and Mutter is such that a GNOME Shell crash will end your whole session, killing running applications and returning you to the login screen.

Yes it can do so. :face_with_raised_eyebrow:

This temporary bug with Gufw which will not work on wayland will now be solved without using;

xhost +si:localuser:root

which also is a security risk. I agree with Will, out of the box users need stability and, may I add , some type of visibly working security interface, Gufw, which has been a staple for noobs and out of the boxers for some time.

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Doesn’t the entire Xorg Window System runs as root though, Dale?

Please consider this stack overflow question https://stackoverflow.com/questions/45465016/how-do-i-get-the-active-window-on-gnome-wayland (and the linked bug in the GNOME bug tracker, https://bugzilla.gnome.org/show_bug.cgi?id=788511) to be a blocker.

I realize that libraries like WNCK may need some kind of privilege escalation or user prompt to work on Wayland which more correctly and thoroughly isolates clients, but eliminating all inter-client communication poses tremendous automation and accessibility problems. Ubuntu already lags badly behind other platforms (COM on Windows, ScriptingBridge on macOS) in terms of end-user automation, and eliminating even the ability to programmatically move windows around is another major step backward.