SUMMARY I updated firefox-nightly on Arch Linux to 90.0a1 (2021-05-13) and I'm getting compositor crash on KDE Plasma Wayland (kwin_wayland) every time firefox-nightly is started. Tested with firefox-nightly --safe-mode and that way kwin_wayland compositor will not crash. So I figured out that it was related to Firefox's gfx.webrender.compositor.force-enabled=true about:config setting. Opening firefox-nightly on XWayland (works) and setting gfx.webrender.compositor.force-enabled=false solved the compositor crashing, so I can start the current nightly version as an Wayland client again. STEPS TO REPRODUCE 0. Start KDE Plasma (Wayland) 1. Install and open firefox-nightly 90.0a1 (2021-05-13) 2. go to about:config and set: - gfx.webrender.compositor = true - gfx.webrender.compositor.force-enabled = true 3. Quit Firefox Nighly (Ctrl+Q) 4. Start Firefox Nightly with `MOZ_ENABLE_WAYLAND=1 firefox-nightly` 5. kwin_wayland will crash and all open apps will die. OBSERVED RESULT kwin_wayland compositor will crash when firefox-nightly is started. My previous firefox-nightly version (90.0a1 (2021-05-07)) was working good even with gfx.webrender.compositor.force-enabled=true. EXPECTED RESULT kwin_wayland should not crash when firefox-nightly starts and all open apps should not die together. SOFTWARE/OS VERSIONS Linux: 5.12.3-arch1 (Arch Linux) KDE Plasma Version: 5.21.5 KDE Frameworks Version: 5.82.0 Qt Version: 5.15.2+kde+r192-1 ADDITIONAL INFORMATION Please, I would appreciate any info on how to debug this.
It's fixed in git master and also 5.22.0
Here is the bug report on Firefox's side: https://bugzilla.mozilla.org/show_bug.cgi?id=1711266 There we figured out that the crash is probably related to kwin_wayland wp_viewporter (un)support protocol, already requested by Bug 434631.
Tested and I can confirm that it is fixed on git master.