SUMMARY *** In the user selection screen, if I pick Wayland, it won't start, it will instead proceed to a black screen and show the cursor before going back to the user selection screen after a minute or so. Then, after trying to start a Wayland session, it is no longer possible to start any kind of graphic session any more, since the x11 session starts showing the same loopy behaviour until rebooting. I tested with my regular session and with 2 newly created users (regular and administration types), without any appreciable difference between the 3. *** STEPS TO REPRODUCE 1. Get to the login screen 2. Select Wayland session 3. Try to log in. OBSERVED RESULT Session won't start, and the user selection screen will be shown again after a few moments. EXPECTED RESULT It should properly login. SOFTWARE/OS VERSIONS Operating System: KDE neon 5.24 KDE Plasma Version: 5.24.5 KDE Frameworks Version: 5.93.0 Qt Version: 5.15.3 Kernel Version: 5.13.0-40-generic (64-bit) Graphics Platform: X11 Processors: 4 × Intel® Core™ i5-4670 CPU @ 3.40GHz Memory: 15.6 GiB of RAM Graphics Processor: NVIDIA GeForce GTX 1060 3GB/PCIe/SSE2
Created attachment 148720 [details] Output of `coredumpctl dump kwin_wayland` after reboot ADDITIONAL INFORMATION Attached the output of `coredumpctl dump kwin_wayland` as suggested by this tread in KDE's subreddit: https://old.reddit.com/r/kde/comments/um14wt/trying_to_start_a_wayland_session_loops_back_to/ Had to compress as 7z because it was too big otherwise. Here is the first part of the output that was displayed in Konsole: ~$ coredumpctl dump kwin_wayland PID: 593064 (kwin_wayland) UID: 1000 (eridani) GID: 1000 (eridani) Signal: 11 (SEGV) Timestamp: Tue 2022-05-10 14:14:15 CDT (19min ago) Command Line: /usr/bin/kwin_wayland --wayland-fd 5 --socket wayland-0 --xwayland-fd 7 --xwayland-fd 8 --xwayland-display :1 --xwayland-xauthority /run/user/1000/xauth_PKLmut --xwayland Executable: /usr/bin/kwin_wayland Control Group: /user.slice/user-1000.slice/session-325.scope Unit: session-325.scope Slice: user-1000.slice Session: 325 Owner UID: 1000 (eridani) Boot ID: e2dbbc468a854738b0afae8032175360 Machine ID: 40718d4cc0cb4ce7bb811319c1acac35 Hostname: pronyma Storage: /var/lib/systemd/coredump/core.kwin_wayland.1000.e2dbbc468a854738b0afae8032175360.593064.1652210055000000000000.lz4 Message: Process 593064 (kwin_wayland) of user 1000 dumped core. Stack trace of thread 593064: #0 0x00007f4633599ef8 _ZN4KWin10GbmSurface17swapBuffersForDrmEv (KWinWaylandDrmBackend.so + 0x57ef8) #1 0x00007f4633596323 _ZN4KWin13EglGbmBackend18endFrameWithBufferEPNS_14AbstractOutputERK7QRegion (KWinWaylandDrmBackend.so + 0x54323) #2 0x00007f46335965fb _ZN4KWin13EglGbmBackend15renderTestFrameEPNS_17DrmAbstractOutputE (KWinWaylandDrmBackend.so + 0x545fb) #3 0x00007f4633587064 _ZN4KWin11DrmPipeline15checkTestBufferEv (KWinWaylandDrmBackend.so + 0x45064) #4 0x00007f46335893be _ZN4KWin11DrmPipeline21commitPipelinesAtomicERK7QVectorIPS0_ENS0_10CommitModeERKS1_IPNS_9DrmObjectEE (KWinWaylandDrmBackend.so + 0x473be) #5 0x00007f463357f916 _ZN4KWin6DrmGpu13testPipelinesEv (KWinWaylandDrmBackend.so + 0x3d916) #6 0x00007f463357fad0 _ZN4KWin6DrmGpu19checkCrtcAssignmentE7QVectorIPNS_12DrmConnectorEES1_IPNS_7DrmCrtcEE (KWinWaylandDrmBackend.so + 0x3dad0) #7 0x00007f463357fee1 _ZN4KWin6DrmGpu19checkCrtcAssignmentE7QVectorIPNS_12DrmConnectorEES1_IPNS_7DrmCrtcEE (KWinWaylandDrmBackend.so + 0x3dee1) #8 0x00007f4633580708 operator() (KWinWaylandDrmBackend.so + 0x3e708) #9 0x00007f4633581c7f _ZN4KWin6DrmGpu13updateOutputsEv (KWinWaylandDrmBackend.so + 0x3fc7f) #10 0x00007f463355dd34 _ZN4KWin10DrmBackend13updateOutputsEv (KWinWaylandDrmBackend.so + 0x1bd34) #11 0x00007f4639cbcdfe n/a (libQt5Core.so.5 + 0x2ebdfe) #12 0x00007f463bfd027e _ZN4KWin10Compositor10setupStartEv (libkwin.so.5 + 0x13f27e) #13 0x00007f463bfd1895 _ZN4KWin17WaylandCompositor5startEv (libkwin.so.5 + 0x140895) #14 0x00007f4639cb3959 _ZN7QObject5eventEP6QEvent (libQt5Core.so.5 + 0x2e2959) #15 0x00007f463a7dcdc3 _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (libQt5Widgets.so.5 + 0x16ddc3) #16 0x00007f463a7e5bd8 _ZN12QApplication6notifyEP7QObjectP6QEvent (libQt5Widgets.so.5 + 0x176bd8) #17 0x00007f4639c85d7a _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt5Core.so.5 + 0x2b4d7a) #18 0x00007f4639c88681 _ZN23QCoreApplicationPrivate16sendPostedEventsEP7QObjectiP11QThreadData (libQt5Core.so.5 + 0x2b7681) #19 0x00007f4639cdd9de _ZN20QEventDispatcherUNIX13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5 + 0x30c9de) #20 0x0000560a7fe2c521 _ZN23QUnixEventDispatcherQPA13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (kwin_wayland + 0x17b521) #21 0x00007f4639c8487b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 + 0x2b387b) #22 0x00007f4639c8ca24 _ZN16QCoreApplication4execEv (libQt5Core.so.5 + 0x2bba24) #23 0x0000560a7fd0cfcc main (kwin_wayland + 0x5bfcc) #24 0x00007f46392430b3 __libc_start_main (libc.so.6 + 0x240b3) #25 0x0000560a7fd0ecfe _start (kwin_wayland + 0x5dcfe) Stack trace of thread 593066: #0 0x00007f46393319cf __GI___poll (libc.so.6 + 0x1129cf) #1 0x00007f463791b36e n/a (libglib-2.0.so.0 + 0x5236e) #2 0x00007f463791b4a3 g_main_context_iteration (libglib-2.0.so.0 + 0x524a3) #3 0x00007f4639ce0642 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5 + 0x30f642) #4 0x00007f4639c8487b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 + 0x2b387b) #5 0x00007f4639a9e442 _ZN7QThread4execEv (libQt5Core.so.5 + 0xcd442) #6 0x00007f463c2a7f4b n/a (libQt5DBus.so.5 + 0x18f4b) #7 0x00007f4639a9f623 n/a (libQt5Core.so.5 + 0xce623) #8 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #9 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593068: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321ac07b n/a (nouveau_dri.so + 0x8b107b) #2 0x00007f46321abedb n/a (nouveau_dri.so + 0x8b0edb) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593067: #0 0x00007f46393319cf __GI___poll (libc.so.6 + 0x1129cf) #1 0x00007f463791b36e n/a (libglib-2.0.so.0 + 0x5236e) #2 0x00007f463791b4a3 g_main_context_iteration (libglib-2.0.so.0 + 0x524a3) #3 0x00007f4639ce0642 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5 + 0x30f642) #4 0x00007f4639c8487b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 + 0x2b387b) #5 0x00007f4639a9e442 _ZN7QThread4execEv (libQt5Core.so.5 + 0xcd442) #6 0x00007f4639a9f623 n/a (libQt5Core.so.5 + 0xce623) #7 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #8 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593069: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321ac07b n/a (nouveau_dri.so + 0x8b107b) #2 0x00007f46321abedb n/a (nouveau_dri.so + 0x8b0edb) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593070: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321ac07b n/a (nouveau_dri.so + 0x8b107b) #2 0x00007f46321abedb n/a (nouveau_dri.so + 0x8b0edb) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593071: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321ac07b n/a (nouveau_dri.so + 0x8b107b) #2 0x00007f46321abedb n/a (nouveau_dri.so + 0x8b0edb) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593072: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321a918b n/a (nouveau_dri.so + 0x8ae18b) #2 0x00007f46321a910b n/a (nouveau_dri.so + 0x8ae10b) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593073: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321a918b n/a (nouveau_dri.so + 0x8ae18b) #2 0x00007f46321a910b n/a (nouveau_dri.so + 0x8ae10b) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593074: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321a918b n/a (nouveau_dri.so + 0x8ae18b) #2 0x00007f46321a910b n/a (nouveau_dri.so + 0x8ae10b) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Stack trace of thread 593075: #0 0x00007f463988a376 futex_wait_cancelable (libpthread.so.0 + 0xf376) #1 0x00007f46321a918b n/a (nouveau_dri.so + 0x8ae18b) #2 0x00007f46321a910b n/a (nouveau_dri.so + 0x8ae10b) #3 0x00007f4639883609 start_thread (libpthread.so.0 + 0x8609) #4 0x00007f463933e163 __clone (libc.so.6 + 0x11f163) Refusing to dump core to tty (use shell redirection or specify --output).
*** This bug has been marked as a duplicate of bug 449797 ***