SUMMARY KWin used to support XDG_SESSION_ID to specify the session to start on. Since https://invent.kde.org/plasma/kwin/-/commit/ade861d6de185cff9e49ec08dd95704f338eff4f this is no longer supported. This is a very useful way to launch KWin through ssh in gdb or through ssh on embedded hardware during the development face. Please see also my older blog post introducing this: https://blog.martin-graesslin.com/blog/2016/04/starting-kwinwayland-on-another-virtual-terminal/ STEPS TO REPRODUCE 1. Use weird vivante hardware which crashes KWin on startup 2. Set XDG_SESSION_ID to a started session 3. Launch KWin through gdb in ssh OBSERVED RESULT KWin doesn't start. EXPECTED RESULT KWin starts on the specified logind session.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/835
Git commit 799db613817a458d9399f683f44b82d141746999 by David Edmundson. Committed on 26/04/2021 at 09:37. Pushed by davidedmundson into branch 'master'. Restore following XDG_SESSION_ID env if set Testing done: Ran on a VT with an XDG_SESSION_ID from another terminal, ensured it switched M +13 -5 src/session_logind.cpp https://invent.kde.org/plasma/kwin/commit/799db613817a458d9399f683f44b82d141746999