Due to Qt-Bug https://bugreports.qt.io/browse/QTBUG-55384 KMail crashes on startup on Wayland. If one specifies "--platform xcb" manually kmail starts and is usable. As we cannot expect users to know that KMail cannot be used on Wayland, we should make kmail default to xcb. Reproducible: Always Steps to Reproduce: 1. Run Plasma Wayland session 2. Try to start kmail Actual Results: KMail crashes Expected Results: KMail does not crash The easiest way to work around the Qt bug is to put a: qputenv("QT_QPA_PLATFORM", "xcb"); before creating the QGuiApplication. This should of course only be done when running on Linux. An example how to do this is in KWin https://quickgit.kde.org/?p=kwin.git&a=blob&h=e4db348bf6dc01b431257e88129a8d7ea14ff92e&hb=a67ccc3529326e6ee8a615ede312aea3b33e844a&f=main_x11.cpp (line 404)
Git commit fd05d3981ecbe880c429f60948dee12b2c7d5df2 by Montel Laurent. Committed on 20/08/2016 at 12:24. Pushed by mlaurent into branch 'Applications/16.08'. Fix Bug 367598 - Kmail needs to force platform xcb on Linux FIXED-IN: 5.3.1 M +4 -0 kmail/src/main.cpp http://commits.kde.org/kdepim/fd05d3981ecbe880c429f60948dee12b2c7d5df2
Since Qt 5.9 web engine works fine with Wayland, and thus so does KMail now, just tested in the Wayland BoF at Akademy :)
(In reply to Volker Krause from comment #2) > Since Qt 5.9 web engine works fine with Wayland, and thus so does KMail now, > just tested in the Wayland BoF at Akademy :) Just tested: I can confirm that web engine now works on Wayland.