Bug 504142

Summary: Login over VNC tries to launch Plasma-kwin_x11.service when it's already running, which doesn't work
Product: [Plasma] plasmashell Reporter: Piotr Dobrogost <bugs.kde.org>
Component: Session ManagementAssignee: Plasma Bugs List <plasma-bugs-null>
Status: REPORTED ---    
Severity: major CC: kdedev, natalie_clarius, nate
Priority: NOR Keywords: X11-only
Version First Reported In: 6.3.5   
Target Milestone: 1.0   
Platform: Fedora RPMs   
OS: Linux   
URL: https://discuss.kde.org/t/kwin-x11-does-not-start-after-upgrading-from-kwin-x11-0-6-3-4-to-kwin-x11-0-6-3-5/34196?u=piotr_dobrogost
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Piotr Dobrogost 2025-05-13 10:10:54 UTC 
Yesterday on Fedora 42 system I did update with `sudo dnf update -y` and today when connecting remotely to this system using TigerVNC I see Plasma splash but then there's no session, only black screen with cursor.
Below is output from `journalctl --user` showing kwin-x11 trying to start a couple of times and then dumping core.
As part of this last system update I see kwin-x11 package was upgraded from `kwin-x11-0:6.3.4` to `kwin-x11-0:6.3.5` and tigervnc was not upgraded so I suspect that kwin-x11 upgrade introduced some bug…

I also raised this at
https://discuss.kde.org/t/kwin-x11-does-not-start-after-upgrading-from-kwin-x11-0-6-3-4-to-kwin-x11-0-6-3-5/34196?u=piotr_dobrogost
and 
https://discussion.fedoraproject.org/t/kwin-x11-does-not-start-after-upgrading-from-kwin-x11-0-6-3-4-to-kwin-x11-0-6-3-5/153376

```
$ kinfo
Operating System: Fedora Linux 42
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.0
Kernel Version: 6.14.5-300.fc42.x86_64 (64-bit)
Graphics Platform: offscreen
Processors: 12 × AMD Ryzen 5 7600 6-Core Processor
Memory: 14.8 GiB of RAM
```

```
maj 13 10:37:10 demon systemd[1330]: Reload requested from client PID 1089381 ('startplasma-x11')...
maj 13 10:37:10 demon systemd[1330]: Reloading...
maj 13 10:37:11 demon systemd[1330]: Reloading finished in 98 ms.
maj 13 10:37:11 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:37:21 demon sudo[1089358]: pam_unix(sudo:session): session closed for user root
maj 13 10:37:33 demon kwin_x11[1089899]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:37:34 demon kwin_x11[1089899]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:37:56 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:37:56 demon kwin_x11[1089899]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:37:56 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:37:56 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:37:56 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:37:56 demon systemd[1330]: plasma-kwin_x11.service: Consumed 585ms CPU time, 92.2M memory peak.
maj 13 10:37:56 demon systemd[1330]: Reached target plasma-workspace-x11.target.
maj 13 10:37:56 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 1.
maj 13 10:37:56 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:37:56 demon systemd[1330]: Started dbus-:1.2-org.kde.KSplash@1.service.
maj 13 10:38:41 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:38:41 demon kwin_x11[1093574]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:38:41 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:38:41 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:38:41 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:38:41 demon systemd[1330]: plasma-kwin_x11.service: Consumed 370ms CPU time, 79M memory peak.
maj 13 10:38:41 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 2.
maj 13 10:38:42 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:38:56 demon plasma_waitforname[1093630]: org.kde.plasma.waitforname: WaitForName: Service was not registered within timeout
maj 13 10:38:56 demon systemd[1330]: dbus-:1.2-org.kde.KSplash@1.service: Main process exited, code=exited, status=1/FAILURE
maj 13 10:38:56 demon systemd[1330]: dbus-:1.2-org.kde.KSplash@1.service: Failed with result 'exit-code'.
maj 13 10:39:27 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:39:27 demon kwin_x11[1097314]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:39:27 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:39:27 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:39:27 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:39:27 demon systemd[1330]: plasma-kwin_x11.service: Consumed 352ms CPU time, 78.6M memory peak.
maj 13 10:39:27 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 3.
maj 13 10:39:27 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:39:27 demon systemd[1330]: Started dbus-:1.2-org.kde.KSplash@2.service.
maj 13 10:40:12 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:40:12 demon kwin_x11[1101017]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:40:12 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:40:12 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:40:12 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:40:12 demon systemd[1330]: plasma-kwin_x11.service: Consumed 348ms CPU time, 78.7M memory peak.
maj 13 10:40:12 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 4.
maj 13 10:40:13 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:40:27 demon plasma_waitforname[1101038]: org.kde.plasma.waitforname: WaitForName: Service was not registered within timeout
maj 13 10:40:27 demon systemd[1330]: dbus-:1.2-org.kde.KSplash@2.service: Main process exited, code=exited, status=1/FAILURE
maj 13 10:40:27 demon systemd[1330]: dbus-:1.2-org.kde.KSplash@2.service: Failed with result 'exit-code'.
maj 13 10:40:40 demon kwin_x11[1104725]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:40:48 demon kwin_x11[1104725]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:40:58 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:40:58 demon kwin_x11[1104725]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:40:58 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:40:58 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:40:58 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:40:58 demon systemd[1330]: plasma-kwin_x11.service: Consumed 389ms CPU time, 87.4M memory peak.
maj 13 10:40:58 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 5.
maj 13 10:40:58 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:40:58 demon systemd[1330]: Started dbus-:1.2-org.kde.KSplash@3.service.
maj 13 10:41:43 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:41:43 demon kwin_x11[1108431]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:41:43 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:41:43 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:41:43 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:41:43 demon systemd[1330]: plasma-kwin_x11.service: Consumed 384ms CPU time, 78.6M memory peak.
maj 13 10:41:43 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 6.
maj 13 10:41:44 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:41:58 demon plasma_waitforname[1108452]: org.kde.plasma.waitforname: WaitForName: Service was not registered within timeout
maj 13 10:41:58 demon systemd[1330]: dbus-:1.2-org.kde.KSplash@3.service: Main process exited, code=exited, status=1/FAILURE
maj 13 10:41:58 demon systemd[1330]: dbus-:1.2-org.kde.KSplash@3.service: Failed with result 'exit-code'.
maj 13 10:42:29 demon systemd[1330]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 10:42:29 demon kwin_x11[1112135]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 10:42:29 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 10:42:29 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 10:42:29 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:42:29 demon systemd[1330]: plasma-kwin_x11.service: Consumed 454ms CPU time, 92.2M memory peak.
maj 13 10:42:29 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 7.
maj 13 10:42:29 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:42:29 demon systemd[1330]: Started dbus-:1.2-org.kde.KSplash@4.service.
maj 13 10:43:07 demon sudo[1119004]:    piotr : TTY=pts/1 ; PWD=/home/piotr ; USER=root ; COMMAND=/usr/bin/systemctl stop vncserver@:1.service
maj 13 10:43:07 demon sudo[1119004]: pam_unix(sudo:session): session opened for user root(uid=0) by piotr(uid=1000)
maj 13 10:43:07 demon kwin_x11[1115854]: The X11 connection broke (error 1). Did the X11 server die?
maj 13 10:43:07 demon sudo[1119004]: pam_unix(sudo:session): session closed for user root
maj 13 10:43:07 demon kwin_x11[1115854]: The X11 connection broke: I/O error (code 1)
maj 13 10:43:07 demon kwin_x11[1115854]: XIO:  fatal IO error 25 (Inappropriate ioctl for device) on X server ":1"
maj 13 10:43:07 demon kwin_x11[1115854]:       after 44 requests (22 known processed) with 0 events remaining.
maj 13 10:43:07 demon kwin_x11[1115854]: QThreadStorage: entry 10 destroyed before end of thread 0x559134872710
maj 13 10:43:07 demon kwin_x11[1115854]: QThreadStorage: entry 9 destroyed before end of thread 0x559134872710
maj 13 10:43:07 demon kwin_x11[1115854]: QThreadStorage: entry 8 destroyed before end of thread 0x559134872710
maj 13 10:43:07 demon kwin_x11[1115854]: QThreadStorage: entry 7 destroyed before end of thread 0x559134872710
maj 13 10:43:07 demon kwin_x11[1115854]: QThreadStorage: entry 1 destroyed before end of thread 0x559134872710
maj 13 10:43:07 demon kwin_x11[1115854]: QThreadStorage: entry 0 destroyed before end of thread 0x559134872710
maj 13 10:43:07 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=exited, status=1/FAILURE
maj 13 10:43:07 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'exit-code'.
maj 13 10:43:07 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 10:43:07 demon systemd[1330]: plasma-kwin_x11.service: Consumed 352ms CPU time, 78.6M memory peak.
maj 13 10:43:08 demon systemd[1330]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 8.
maj 13 10:43:08 demon systemd[1330]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 10:43:08 demon kwin_x11[1119019]: qt.qpa.xcb: could not connect to display :1
maj 13 10:43:08 demon kwin_x11[1119019]: qt.qpa.plugin: From 6.5.0, xcb-cursor0 or libxcb-cursor0 is needed to load the Qt xcb platform plugin.
maj 13 10:43:08 demon kwin_x11[1119019]: qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
maj 13 10:43:08 demon kwin_x11[1119019]: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

                                         Available platform plugins are: wayland-egl, wayland, eglfs, linuxfb, minimal, minimalegl, offscreen, vkkhrdisplay, vnc, xcb.
maj 13 10:43:08 demon systemd-coredump[1119062]: [🡕] Process 1119019 (kwin_x11) of user 1000 dumped core.

                                                 Module /usr/bin/kwin_x11 from rpm kwin-x11-6.3.5-1.fc42.x86_64
                                                 Module libuuid.so.1 from rpm util-linux-2.40.4-7.fc42.x86_64
                                                 Module libICE.so.6 from rpm libICE-1.1.2-2.fc42.x86_64
                                                 Module libSM.so.6 from rpm libSM-1.2.5-2.fc42.x86_64
                                                 Module libX11-xcb.so.1 from rpm libX11-1.8.11-1.fc42.x86_64
                                                 Module libQt6XcbQpa.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libqxcb.so from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libcrypt.so.2 from rpm libxcrypt-4.4.38-7.fc42.x86_64
                                                 Module libsasl2.so.3 from rpm cyrus-sasl-2.1.28-30.fc42.x86_64
                                                 Module libevent-2.1.so.7 from rpm libevent-2.1.12-15.fc42.x86_64
                                                 Module libunistring.so.5 from rpm libunistring-1.1-9.fc42.x86_64
                                                 Module libgmodule-2.0.so.0 from rpm glib2-2.84.1-1.fc42.x86_64
                                                 Module libpsl.so.5 from rpm libpsl-0.21.5-5.fc42.x86_64
                                                 Module libssh.so.4 from rpm libssh-0.11.1-4.fc42.x86_64
                                                 Module libidn2.so.0 from rpm libidn2-2.3.8-1.fc42.x86_64
                                                 Module libnghttp2.so.14 from rpm nghttp2-1.64.0-3.fc42.x86_64
                                                 Module libimobiledevice-glue-1.0.so.0 from rpm libimobiledevice-glue-1.3.1-2.fc42.x86_64
                                                 Module libusbmuxd-2.0.so.7 from rpm libusbmuxd-2.1.0-3.fc42.x86_64
                                                 Module libssl.so.3 from rpm openssl-3.2.4-3.fc42.x86_64
                                                 Module libduktape.so.207 from rpm duktape-2.7.0-9.fc42.x86_64
                                                 Module libgio-2.0.so.0 from rpm glib2-2.84.1-1.fc42.x86_64
                                                 Module libcurl.so.4 from rpm curl-8.11.1-4.fc42.x86_64
                                                 Module libKF6BreezeIcons.so.6 from rpm kf6-breeze-icons-6.13.0-2.fc42.x86_64
                                                 Module libselinux.so.1 from rpm libselinux-3.8-1.fc42.x86_64
                                                 Module libblkid.so.1 from rpm util-linux-2.40.4-7.fc42.x86_64
                                                 Module libattr.so.1 from rpm attr-2.5.2-5.fc42.x86_64
                                                 Module libplist-2.0.so.4 from rpm libplist-2.6.0-2.fc42.x86_64
                                                 Module libimobiledevice-1.0.so.6 from rpm libimobiledevice-1.3.0^20240916gited9703d-5.fc42.x86_64
                                                 Module libpxbackend-1.0.so from rpm libproxy-0.5.8-2.fc42.x86_64
                                                 Module libbrotlicommon.so.1 from rpm brotli-1.1.0-6.fc42.x86_64
                                                 Module libkeyutils.so.1 from rpm keyutils-1.6.3-5.fc42.x86_64
                                                 Module libkrb5support.so.0 from rpm krb5-1.21.3-5.fc42.x86_64
                                                 Module libcom_err.so.2 from rpm e2fsprogs-1.47.2-3.fc42.x86_64
                                                 Module libk5crypto.so.3 from rpm krb5-1.21.3-5.fc42.x86_64
                                                 Module libkrb5.so.3 from rpm krb5-1.21.3-5.fc42.x86_64
                                                 Module libKF6IconThemes.so.6 from rpm kf6-kiconthemes-6.13.0-2.fc42.x86_64
                                                 Module libKF6IconWidgets.so.6 from rpm kf6-kiconthemes-6.13.0-2.fc42.x86_64
                                                 Module libKF6ItemViews.so.6 from rpm kf6-kitemviews-6.13.0-1.fc42.x86_64
                                                 Module libQt6PrintSupport.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libgobject-2.0.so.0 from rpm glib2-2.84.1-1.fc42.x86_64
                                                 Module libgudev-1.0.so.0 from rpm libgudev-238-7.fc42.x86_64
                                                 Module libxcb-util.so.1 from rpm xcb-util-0.4.1-7.fc42.x86_64
                                                 Module libmount.so.1 from rpm util-linux-2.40.4-7.fc42.x86_64
                                                 Module libacl.so.1 from rpm acl-2.3.2-3.fc42.x86_64
                                                 Module libKF6AuthCore.so.6 from rpm kf6-kauth-6.13.0-1.fc42.x86_64
                                                 Module libKF6Solid.so.6 from rpm kf6-solid-6.13.0-1.fc42.x86_64
                                                 Module libwayland-cursor.so.0 from rpm wayland-1.23.1-1.fc42.x86_64
                                                 Module libicudata.so.76 from rpm icu-76.1-4.fc42.x86_64
                                                 Module libgraphite2.so.3 from rpm graphite2-1.3.14-18.fc42.x86_64
                                                 Module libpcre2-8.so.0 from rpm pcre2-10.45-1.fc42.x86_64
                                                 Module libxml2.so.2 from rpm libxml2-2.12.10-1.fc42.x86_64
                                                 Module libGLdispatch.so.0 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libproxy.so.1 from rpm libproxy-0.5.8-2.fc42.x86_64
                                                 Module libbrotlidec.so.1 from rpm brotli-1.1.0-6.fc42.x86_64
                                                 Module libgssapi_krb5.so.2 from rpm krb5-1.21.3-5.fc42.x86_64
                                                 Module libQt6QmlWorkerScript.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libKF6XmlGui.so.6 from rpm kf6-kxmlgui-6.13.0-2.fc42.x86_64
                                                 Module libKF6IdleTime.so.6 from rpm kf6-kidletime-6.13.0-1.fc42.x86_64
                                                 Module libwacom.so.9 from rpm libwacom-2.15.0-1.fc42.x86_64
                                                 Module libevdev.so.2 from rpm libevdev-1.13.4-1.fc42.x86_64
                                                 Module libmtdev.so.1 from rpm mtdev-1.1.6-10.fc42.x86_64
                                                 Module libexpat.so.1 from rpm expat-2.7.1-1.fc42.x86_64
                                                 Module libxcb-image.so.0 from rpm xcb-util-image-0.4.1-7.fc42.x86_64
                                                 Module libxcb-render-util.so.0 from rpm xcb-util-renderutil-0.3.10-7.fc42.x86_64
                                                 Module libKF6KIOCore.so.6 from rpm kf6-kio-6.13.0-2.fc42.x86_64
                                                 Module libKF6JobWidgets.so.6 from rpm kf6-kjobwidgets-6.13.0-2.fc42.x86_64
                                                 Module libKF6KIOGui.so.6 from rpm kf6-kio-6.13.0-2.fc42.x86_64
                                                 Module libcap.so.2 from rpm libcap-2.73-2.fc42.x86_64
                                                 Module libffi.so.8 from rpm libffi-3.4.6-5.fc42.x86_64
                                                 Module libogg.so.0 from rpm libogg-1.3.5-11.fc42.x86_64
                                                 Module libvorbis.so.0 from rpm libvorbis-1.3.7-12.fc42.x86_64
                                                 Module libQt6WaylandClient.so.6 from rpm qt6-qtwayland-6.9.0-3.fc42.x86_64
                                                 Module liblzma.so.5 from rpm xz-5.8.1-2.fc42.x86_64
                                                 Module libbz2.so.1 from rpm bzip2-1.0.8-20.fc42.x86_64
                                                 Module libcrypto.so.3 from rpm openssl-3.2.4-3.fc42.x86_64
                                                 Module libpcre2-16.so.0 from rpm pcre2-10.45-1.fc42.x86_64
                                                 Module libb2.so.1 from rpm libb2-0.98.1-13.fc42.x86_64
                                                 Module libdouble-conversion.so.3 from rpm double-conversion-3.3.1-1.fc42.x86_64
                                                 Module libsystemd.so.0 from rpm systemd-257.5-6.fc42.x86_64
                                                 Module libzstd.so.1 from rpm zstd-1.5.7-1.fc42.x86_64
                                                 Module libicuuc.so.76 from rpm icu-76.1-4.fc42.x86_64
                                                 Module libicui18n.so.76 from rpm icu-76.1-4.fc42.x86_64
                                                 Module libdbus-1.so.3 from rpm dbus-1.16.0-3.fc42.x86_64
                                                 Module libz.so.1 from rpm zlib-ng-2.2.4-3.fc42.x86_64
                                                 Module libfreetype.so.6 from rpm freetype-2.13.3-2.fc42.x86_64
                                                 Module libharfbuzz.so.0 from rpm harfbuzz-10.4.0-1.fc42.x86_64
                                                 Module libpng16.so.16 from rpm libpng-1.6.44-2.fc42.x86_64
                                                 Module libOpenGL.so.0 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libGLX.so.0 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libglib-2.0.so.0 from rpm glib2-2.84.1-1.fc42.x86_64
                                                 Module libfontconfig.so.1 from rpm fontconfig-2.16.0-2.fc42.x86_64
                                                 Module libEGL.so.1 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libKF6Codecs.so.6 from rpm kf6-kcodecs-6.13.0-1.fc42.x86_64
                                                 Module libKF6WidgetsAddons.so.6 from rpm kf6-kwidgetsaddons-6.13.0-2.fc42.x86_64
                                                 Module libXfixes.so.3 from rpm libXfixes-6.0.1-5.fc42.x86_64
                                                 Module libxcb-res.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libQt6Xml.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6Network.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6QmlModels.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libQt6QmlMeta.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libKF6Notifications.so.6 from rpm kf6-knotifications-6.13.0-2.fc42.x86_64
                                                 Module libKF6Package.so.6 from rpm kf6-kpackage-6.13.0-1.fc42.x86_64
                                                 Module libxcvt.so.0 from rpm libxcvt-0.1.2-9.fc42.x86_64
                                                 Module libdisplay-info.so.2 from rpm libdisplay-info-0.2.0-3.fc42.x86_64
                                                 Module libQt6OpenGL.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libb2.so.1 from rpm libb2-0.98.1-13.fc42.x86_64
                                                 Module libdouble-conversion.so.3 from rpm double-conversion-3.3.1-1.fc42.x86_64
                                                 Module libsystemd.so.0 from rpm systemd-257.5-6.fc42.x86_64
                                                 Module libzstd.so.1 from rpm zstd-1.5.7-1.fc42.x86_64
                                                 Module libicuuc.so.76 from rpm icu-76.1-4.fc42.x86_64
                                                 Module libicui18n.so.76 from rpm icu-76.1-4.fc42.x86_64
                                                 Module libdbus-1.so.3 from rpm dbus-1.16.0-3.fc42.x86_64
                                                 Module libz.so.1 from rpm zlib-ng-2.2.4-3.fc42.x86_64
                                                 Module libfreetype.so.6 from rpm freetype-2.13.3-2.fc42.x86_64
                                                 Module libharfbuzz.so.0 from rpm harfbuzz-10.4.0-1.fc42.x86_64
                                                 Module libpng16.so.16 from rpm libpng-1.6.44-2.fc42.x86_64
                                                 Module libOpenGL.so.0 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libGLX.so.0 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libglib-2.0.so.0 from rpm glib2-2.84.1-1.fc42.x86_64
                                                 Module libfontconfig.so.1 from rpm fontconfig-2.16.0-2.fc42.x86_64
                                                 Module libEGL.so.1 from rpm libglvnd-1.7.0-7.fc42.x86_64
                                                 Module libKF6Codecs.so.6 from rpm kf6-kcodecs-6.13.0-1.fc42.x86_64
                                                 Module libKF6WidgetsAddons.so.6 from rpm kf6-kwidgetsaddons-6.13.0-2.fc42.x86_64
                                                 Module libXfixes.so.3 from rpm libXfixes-6.0.1-5.fc42.x86_64
                                                 Module libxcb-res.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libQt6Xml.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6Network.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6QmlModels.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libQt6QmlMeta.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libKF6Notifications.so.6 from rpm kf6-knotifications-6.13.0-2.fc42.x86_64
                                                 Module libKF6Package.so.6 from rpm kf6-kpackage-6.13.0-1.fc42.x86_64
                                                 Module libxcvt.so.0 from rpm libxcvt-0.1.2-9.fc42.x86_64
                                                 Module libdisplay-info.so.2 from rpm libdisplay-info-0.2.0-3.fc42.x86_64
                                                 Module libQt6OpenGL.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libKScreenLocker.so.6 from rpm kscreenlocker-6.3.5-1.fc42.x86_64
                                                 Module libPlasmaActivities.so.6 from rpm plasma-activities-6.3.5-1.fc42.x86_64
                                                 Module libxcb-xinput.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-present.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-dri3.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libwayland-client.so.0 from rpm wayland-1.23.1-1.fc42.x86_64
                                                 Module libKWaylandClient.so.6 from rpm kwayland-6.3.5-1.fc42.x86_64
                                                 Module libinput.so.10 from rpm libinput-1.28.1-1.fc42.x86_64
                                                 Module libgbm.so.1 from rpm mesa-25.0.4-2.fc42.x86_64
                                                 Module libdrm.so.2 from rpm libdrm-2.4.124-2.fc42.x86_64
                                                 Module libxcb-xinerama.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-sync.so.1 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-shm.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-icccm.so.4 from rpm xcb-util-wm-0.4.2-7.fc42.x86_64
                                                 Module libxcb-glx.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-damage.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-cursor.so.0 from rpm xcb-util-cursor-0.1.5-3.fc42.x86_64
                                                 Module libKGlobalAccelD.so.0 from rpm kglobalacceld-6.3.5-1.fc42.x86_64
                                                 Module liblcms2.so.2 from rpm lcms2-2.16-5.fc42.x86_64
                                                 Module libudev.so.1 from rpm systemd-257.5-6.fc42.x86_64
                                                 Module libkdecorations3private.so.2 from rpm kdecoration-6.3.5-1.fc42.x86_64
                                                 Module libKF6I18nQml.so.6 from rpm kf6-ki18n-6.13.0-1.fc42.x86_64
                                                 Module libKF6ConfigQml.so.6 from rpm kf6-kconfig-6.13.0-1.fc42.x86_64
                                                 Module libQt6Sensors.so.6 from rpm qt6-qtsensors-6.9.0-1.fc42.x86_64
                                                 Module libwayland-server.so.0 from rpm wayland-1.23.1-1.fc42.x86_64
                                                 Module libltdl.so.7 from rpm libtool-2.5.4-4.fc42.x86_64
                                                 Module libtdb.so.1 from rpm libtdb-1.4.13-2.fc42.x86_64
                                                 Module libvorbisfile.so.3 from rpm libvorbis-1.3.7-12.fc42.x86_64
                                                 Module libKF6GuiAddons.so.6 from rpm kf6-kguiaddons-6.13.0-2.fc42.x86_64
                                                 Module libKF6ColorScheme.so.6 from rpm kf6-kcolorscheme-6.13.0-2.fc42.x86_64
                                                 Module libKF6Archive.so.6 from rpm kf6-karchive-6.13.0-1.fc42.x86_64
                                                 Module libQt6Svg.so.6 from rpm qt6-qtsvg-6.9.0-1.fc42.x86_64
                                                 Module libXext.so.6 from rpm libXext-1.3.6-3.fc42.x86_64
                                                 Module libXau.so.6 from rpm libXau-1.0.12-2.fc42.x86_64
                                                 Module libQt6Core.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6DBus.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6Gui.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libQt6Widgets.so.6 from rpm qt6-qtbase-6.9.0-2.fc42.x86_64
                                                 Module libqaccessibilityclient-qt6.so.0 from rpm qaccessibilityclient-0.6.0-3.fc42.x86_64
                                                 Module libKF6ConfigCore.so.6 from rpm kf6-kconfig-6.13.0-1.fc42.x86_64
                                                 Module libKF6ConfigGui.so.6 from rpm kf6-kconfig-6.13.0-1.fc42.x86_64
                                                 Module libKF6I18n.so.6 from rpm kf6-ki18n-6.13.0-1.fc42.x86_64
                                                 Module libKF6CoreAddons.so.6 from rpm kf6-kcoreaddons-6.13.0-2.fc42.x86_64
                                                 Module libKF6ConfigWidgets.so.6 from rpm kf6-kconfigwidgets-6.13.0-2.fc42.x86_64
                                                 Module libKF6GlobalAccel.so.6 from rpm kf6-kglobalaccel-6.13.0-2.fc42.x86_64
                                                 Module libX11.so.6 from rpm libX11-1.8.11-1.fc42.x86_64
                                                 Module libKF6WindowSystem.so.6 from rpm kf6-kwindowsystem-6.13.0-2.fc42.x86_64
                                                 Module libKF6Service.so.6 from rpm kf6-kservice-6.13.0-1.fc42.x86_64
                                                 Module libQt6Qml.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libQt6Quick.so.6 from rpm qt6-qtdeclarative-6.9.0-2.fc42.x86_64
                                                 Module libkdecorations3.so.6 from rpm kdecoration-6.3.5-1.fc42.x86_64
                                                 Module libepoxy.so.0 from rpm libepoxy-1.5.10-9.fc42.x86_64
                                                 Module libKF6Crash.so.6 from rpm kf6-kcrash-6.13.0-1.fc42.x86_64
                                                 Module libkwin.so.6 from rpm kwin-6.3.5-1.fc42.x86_64
                                                 Module libKF6Svg.so.6 from rpm kf6-ksvg-6.13.0-1.fc42.x86_64
                                                 Module libXi.so.6 from rpm libXi-1.8.2-2.fc42.x86_64
                                                 Module libxcb.so.1 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-randr.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-keysyms.so.1 from rpm xcb-util-keysyms-0.4.1-7.fc42.x86_64
                                                 Module libxcb-shape.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-render.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-xfixes.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxcb-composite.so.0 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Module libxkbcommon.so.0 from rpm libxkbcommon-1.8.1-1.fc42.x86_64
                                                 Module libxkbcommon-x11.so.0 from rpm libxkbcommon-1.8.1-1.fc42.x86_64
                                                 Module libxcb-xkb.so.1 from rpm libxcb-1.17.0-5.fc42.x86_64
                                                 Stack trace of thread 1119019:
                                                 #0  0x00007f6eada8111c __pthread_kill_implementation (libc.so.6 + 0x7311c)
                                                 #1  0x00007f6eada27afe raise (libc.so.6 + 0x19afe)
                                                 #2  0x00007f6eada0f6d0 abort (libc.so.6 + 0x16d0)
                                                 #3  0x00007f6eae01abfc _Z6qAbortv (libQt6Core.so.6 + 0x1abfc)
                                                 #4  0x00007f6eae06e308 _ZL10qt_message9QtMsgTypeRK18QMessageLogContextPKcP13__va_list_tag (libQt6Core.so.6 + 0x6e308)
                                                 #5  0x00007f6eae01c334 _ZNK14QMessageLogger5fatalEPKcz (libQt6Core.so.6 + 0x1c334)
                                                 #6  0x00007f6eae82dc6d _ZL13init_platformRK7QStringS1_S1_RiPPc.cold (libQt6Gui.so.6 + 0x2dc6d)
                                                 #7  0x00007f6eae8e269b _ZN22QGuiApplicationPrivate25createPlatformIntegrationEv (libQt6Gui.so.6 + 0xe269b)
                                                 #8  0x00007f6eae8e3188 _ZN22QGuiApplicationPrivate21createEventDispatcherEv (libQt6Gui.so.6 + 0xe3188)
                                                 #9  0x00007f6eae0fed65 _ZN23QCoreApplicationPrivate4initEv (libQt6Core.so.6 + 0xfed65)
                                                 #10 0x00007f6eae8e746d _ZN22QGuiApplicationPrivate4initEv (libQt6Gui.so.6 + 0xe746d)
                                                 #11 0x00007f6eaf243755 _ZN19QApplicationPrivate4initEv (libQt6Widgets.so.6 + 0x43755)
                                                 #12 0x00007f6eb0f60a55 _ZN4KWin11ApplicationC1ENS0_13OperationModeERiPPc (libkwin.so.6 + 0x160a55)
                                                 #13 0x0000564e568f294b main (/usr/bin/kwin_x11 + 0xc94b)
                                                 #14 0x00007f6eada115f5 __libc_start_call_main (libc.so.6 + 0x35f5)
                                                 #15 0x00007f6eada116a8 __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x36a8)
                                                 #16 0x0000564e568f7125 _start (/usr/bin/kwin_x11 + 0x11125)

                                                 Stack trace of thread 1119047:
                                                 #0  0x00007f6eada876c2 __syscall_cancel_arch (libc.so.6 + 0x796c2)
                                                 #1  0x00007f6eada7b9da __internal_syscall_cancel (libc.so.6 + 0x6d9da)
                                                 #2  0x00007f6eada7ba24 __syscall_cancel (libc.so.6 + 0x6da24)
                                                 #3  0x00007f6eadaf5176 ppoll (libc.so.6 + 0xe7176)
                                                 #4  0x00007f6eaccf5210 g_main_context_iterate_unlocked.isra.0 (libglib-2.0.so.0 + 0x4a210)
                                                 #5  0x00007f6eaccf52d3 g_main_context_iteration (libglib-2.0.so.0 + 0x4a2d3)
                                                 #6  0x00007f6eae3ff56d _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x3ff56d)
                                                 #7  0x00007f6eae103783 _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x103783)
                                                 #8  0x00007f6eae2217fd _ZN7QThread4execEv (libQt6Core.so.6 + 0x2217fd)
                                                 #9  0x00007f6eafa27901 _ZN22QDBusConnectionManager3runEv (libQt6DBus.so.6 + 0x20901)
                                                 #10 0x00007f6eae2bdde4 _ZN14QThreadPrivate5startEPv (libQt6Core.so.6 + 0x2bdde4)
                                                 #11 0x00007f6eada7f1d4 start_thread (libc.so.6 + 0x711d4)
                                                 #12 0x00007f6eadb01cec __clone3 (libc.so.6 + 0xf3cec)
                                                 ELF object binary architecture: AMD x86-64
maj 13 10:43:08 demon systemd[1330]: plasma-kwin_x11.service: Main process exited, code=dumped, status=6/ABRT
maj 13 10:43:08 demon systemd[1330]: plasma-kwin_x11.service: Failed with result 'core-dump'.
maj 13 10:43:08 demon systemd[1330]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
```
Comment 1 Piotr Dobrogost 2025-05-13 12:49:59 UTC 
I enabled debug output from kwin with systemd drop-in file:
```
$ cat /home/piotr/.config/systemd/user/plasma-kwin_x11.service.d/override.conf
[Service]
Environment="QT_LOGGING_RULES=kwin_*.debug=true"
```
However after doing this I don't see any information that might help diagnose the problem in the output of `journalctl --user` (below).
No warnings nor errors and then timeout:
`maj 13 14:38:47 demon systemd[1315]: plasma-kwin_x11.service: start operation timed out. Terminating.`


```
maj 13 14:38:02 demon systemd[1315]: Starting plasma-kwin_x11.service - KDE Window Manager...
maj 13 14:38:02 demon kwin_x11[619433]: kwin_platform_x11_standalone: Has XInput support 2 . 2
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Extensions: shape: 0x "11"  composite: 0x "4"  render: 0x "b"  fixes: 0x "50"  randr: 0x "14"  sync: 0x "31"  damage: 0x  "11"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_xkbcommon: XKB: created compose table from locale en_DK.UTF-8 with path /usr/share/X11/locale/en_US.UTF-8/Compose
maj 13 14:38:02 demon kwin_x11[619433]: kwin_decorations: Trying to load decoration plugin:  "/usr/lib64/qt6/plugins/org.kde.kdecoration3/org.kde.breeze.so"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Attempting to load the OpenGL scene
maj 13 14:38:02 demon kwin_x11[619433]: kwin_platform_x11_standalone: Choosing GLXFBConfig 0xef X visual 0x2fe depth 24 RGBA 8:8:8:0 ZS 0:0 sRGB: 1
maj 13 14:38:02 demon kwin_x11[619433]: kwin_platform_x11_standalone: Global share context format: QSurfaceFormat(version 4.6, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 0, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 0, stencilBufferSize 0, samples -1, swapBehavior QSurfaceFormat::DefaultSwapBehavior, swapInterval 0, colorSpace QColorSpace(), profile  QSurfaceFormat::CompatibilityProfile)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_platform_x11_standalone: Created GLX context with attributes:
                                        Version requested:        true
                                        Version:        3.1
                                        Robust:        false
                                        Reset on video memory purge:        false
                                        Forward compatible:        false
                                        Core profile:        false
                                        Compatibility profile:        false
                                        High priority:        false
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 224 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 1 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 48 VGPRS: 12 Code Size: 3100 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 4 DivergentLoop: 0 (PS, W64)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: OpenGL compositing has been successfully initialized
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "blendchanges"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 208 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 1 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 208 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 1 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 24 VGPRS: 20 Code Size: 316 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 0 DivergentLoop: 0 (PS, W64)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 24 VGPRS: 32 Code Size: 452 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 0 DivergentLoop: 0 (PS, W64)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 188 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "blur"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "colorpicker"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 24 VGPRS: 16 Code Size: 168 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 0 DivergentLoop: 0 (PS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 276 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 1 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 20 Code Size: 452 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 1 DivergentLoop: 0 (PS, W64)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "contrast"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "highlightwindow"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "kscreen"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "outputlocator"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "overview"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "screenedge"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "screenshot"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Effect is not supported:  "screentransform"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Effect is not supported:  "shakecursor"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "slide"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "slidingpopups"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "startupfeedback"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "systembell"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "tileseditor"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "windowview"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded plugin effect:  "zoom"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_platform_x11_standalone: Using FBConfig 0x28e for visual 0x39c
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 224 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 1 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 8 Code Size: 288 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 1 DivergentLoop: 0 (PS, W64)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 8 VGPRS: 8 Code Size: 52 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 0 DivergentLoop: 0 (PS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 16 VGPRS: 16 Code Size: 132 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 16 VGPRS: 4 Code Size: 96 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 1 DivergentLoop: 0 (PS, W64)
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "dialogparent"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "fadingpopups"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "frozenapp"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "fullscreen"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "login"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "logout"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "sessionquit"
maj 13 14:38:02 demon kwin_x11[619433]: kwin_core: Successfully loaded scripted effect:  "windowaperture"
maj 13 14:38:33 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 32 VGPRS: 16 Code Size: 224 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 1 PSOutputs: 0 InlineUniforms: 0 DivergentLoop: 0 (VS, W32)
maj 13 14:38:33 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 40 VGPRS: 8 Code Size: 308 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 1 DivergentLoop: 0 (PS, W64)
maj 13 14:38:33 demon kwin_x11[619433]: kwin_scene_opengl: 0x1: Shader Stats: SGPRS: 16 VGPRS: 4 Code Size: 144 LDS: 0 Scratch: 0 Max Waves: 16 Spilled SGPRs: 0 Spilled VGPRs: 0 PrivMem VGPRs: 0 LSOutputs: 0 HSOutputs: 0 HSPatchOuts: 0 ESOutputs: 0 GSOutputs: 0 VSOutputs: 0 PSOutputs: 1 InlineUniforms: 1 DivergentLoop: 0 (PS, W64)
maj 13 14:38:47 demon systemd[1315]: plasma-kwin_x11.service: start operation timed out. Terminating.
maj 13 14:38:47 demon kwin_x11[619433]: kwin_scene_opengl: Could not delete framebuffer because no context is current
maj 13 14:38:47 demon systemd[1315]: plasma-kwin_x11.service: Main process exited, code=exited, status=15/n/a
maj 13 14:38:47 demon systemd[1315]: plasma-kwin_x11.service: Failed with result 'timeout'.
maj 13 14:38:47 demon systemd[1315]: Failed to start plasma-kwin_x11.service - KDE Window Manager.
maj 13 14:38:47 demon systemd[1315]: plasma-kwin_x11.service: Consumed 362ms CPU time, 85.8M memory peak.
maj 13 14:38:47 demon systemd[1315]: plasma-kwin_x11.service: Scheduled restart job, restart counter is at 1.
```
Comment 2 Nate Graham 2025-05-13 19:36:42 UTC 
Since it's crashing, can you get a backtrace of the crash? We need one in order for this to be actionable. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl
Comment 3 Piotr Dobrogost 2025-05-13 19:52:30 UTC 
(In reply to Nate Graham from comment #2)
> Since it's crashing, can you get a backtrace of the crash? We need one in
> order for this to be actionable. See
> https://community.kde.org/Guidelines_and_HOWTOs/Debugging/
> How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl

It crashed eventually but first it had failed to start 7 times in a row. I guess the final crash was due to some kind of accumulation of… something?
I'm afraid that fixing crash alone won't solve the problem as it will just keep timing out each time it's started.
It would be much better to investigate why it's unable to start when it does not crash.
If it's waiting for something I hoped it would have been in the debug log but I don't see anything like this.
Can some more debug logging be added if kwin_x11 process does indeed wait for something?
Can you point me to changes in kwin_x11 between 6.3.4 and 6.3.5?
Comment 4 Piotr Dobrogost 2025-05-13 20:20:00 UTC 
It turns out there was autologin enabled on remote machine so there was already active plasma (wayland) session when starting plasma-kwin_x11 service. After first logging out from active session with `dbus-send --dest=org.kde.Shutdown /Shutdown org.kde.Shutdown.logout` and then starting `vncserver@:1.service` the plasma-kwin_x11 service successfully started.

Can this situation be detected and logged so that it would be obvious what's going on?