Ten years' worth of effort to replace the Xorg graphics framework has been given a “must try harder” mark by Ubuntu, which says its next release will not use Wayland by default.
Ubuntu's desktop engineering manager Will Cooke made the announcement last Friday, saying the decision applies to the Bionic Beaver release due in April.
He listed three shortcomings in Wayland: screen sharing works (for example in Skype, Hangouts and WebRTC) better in Xorg, remote desktop control ditto, and “recoverability from Shell crashes is less dramatic”.
Screen sharing is the big killer: in Wayland, both the screen sharing protocol and the GNOME implementation (PipeWire) are still under development. PipeWire was formally unveiled as a project in September 2017.
Once development is completed, Cooke wrote, there's still going to be a lag while third-party developers integrate the screen sharing.
As for crash recovery: under Xorg, the shell can be recovered independently of the display server and running applications. Wayland hasn't reached that point yet, so if it falls over, so do any applications the user has loaded.
“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”, Cooke wrote. “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[s] in progress and we continue to contribute to this work upstream.”
He emphasised that Ubuntu will still work on Wayland “by adding features and fixing bugs”.
Bionic Beaver is formally numbered 18.04, and Cooke said the decision will be re-evaluated for Ubuntu 18.10. ®