Description of problem:
I booted into the Fedora Rawhide/31 KDE Plasma spin image Fedora-KDE-Live-x86_64-Rawhide-20190724.n.0.iso at
I ran sudo dnf install x*amd* kwin*way* pla*way* which installed
I logged out of Plasma. I was going to log in to Plasma on Wayland from sddm as I usually do, but the Fedora live image is set to autologin to Plasma on X. I restarted sddm so that the X amdgpu driver would be used instead of the X modesetting driver since the system has a Radeon R5 GPU. I switched to VT2 and I ran sudo systemctl restart sddm. Plasma on X logged in automatically but Plasma froze on the splash screen. I ran sudo systemctl stop sddm in VT2. I ran startplasmacompositor & from VT2. Plasma on Wayland started, but drkonqi showed a segmentation fault in plasmashell in ScreenPool::ScreenPool at /usr/src/debug/plasma-workspace-5.16.2-2.fc31.x86_64/shell/screenpool.cpp:48.
I think that the plasmashell crash was more likely to have happened when the autologin to Plasma on X got stuck on the splash screen and I stopped sddm than when I ran startplasmacompositor. The trace of the segmentation fault doesn't appear to have any Wayland-specific functions. The Wayland session appeared normally. I just didn't see drkonqi until the Wayland session started. plasmashell and drkonqi aborted after I stopped sddm and before I ran startplasmacompositor the next time I tried to reproduce the crash. The Plasma on X autologin splash screen freeze has happened several times after restarting sddm with two Fedora rawhide live images. The circle stopped spinning after a few seconds, and the desktop didn't appear.
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f4a48b7dd00 (LWP 3462))]
Thread 2 (Thread 0x7f4a359f6700 (LWP 3721)):
#0 0x00007f4a466fd79f in poll () from /lib64/libc.so.6
#1 0x00007f4a453102ee in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#2 0x00007f4a45310423 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#3 0x00007f4a46c90bd3 in QEventDispatcherGlib::processEvents (this=0x7f4a300018e0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#4 0x00007f4a46c3a9db in QEventLoop::exec (this=this@entry=0x7f4a359f5cf0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#5 0x00007f4a46a93625 in QThread::exec (this=this@entry=0x7f4a4752a060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#6 0x00007f4a474a6f4a in QDBusConnectionManager::run (this=0x7f4a4752a060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#7 0x00007f4a46a94776 in QThreadPrivate::start (arg=0x7f4a4752a060 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:361
#8 0x00007f4a45ef04e2 in start_thread () from /lib64/libpthread.so.0
#9 0x00007f4a46708333 in clone () from /lib64/libc.so.6
Thread 1 (Thread 0x7f4a48b7dd00 (LWP 3462)):
#5 ScreenPool::ScreenPool (this=0x55f81a24adb0, config=..., parent=<optimized out>) at /usr/src/debug/plasma-workspace-5.16.2-2.fc31.x86_64/shell/screenpool.cpp:48
#6 0x000055f8198ba860 in ShellCorona::ShellCorona (this=0x55f81a21ff50, parent=<optimized out>) at /usr/include/qt5/QtCore/qarraydata.h:257
#7 0x000055f8198c7b9f in ShellManager::loadHandlers (this=0x7f4a3000b050) at /usr/src/debug/plasma-workspace-5.16.2-2.fc31.x86_64/shell/shellmanager.cpp:93
#8 0x000055f81988f5a5 in ShellManager::qt_static_metacall (_o=<optimized out>, _id=<optimized out>, _a=<optimized out>, _c=<optimized out>) at /usr/src/debug/plasma-workspace-5.16.2-2.fc31.x86_64/x86_64-redhat-linux-gnu/shell/plasmashell_autogen/EWIEGA46WW/moc_shellmanager.cpp:104
#9 0x00007f4a46c66bda in QObject::event (this=0x7f4a3000b050, e=<optimized out>) at kernel/qobject.cpp:1260
#10 0x00007f4a47736af6 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#11 0x00007f4a4773fe80 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#12 0x00007f4a46c3bad8 in QCoreApplication::notifyInternal2 (receiver=0x7f4a3000b050, event=0x55f81a1dd8f0) at kernel/qcoreapplication.cpp:1084
#13 0x00007f4a46c3ea7b in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x55f81a100b90) at kernel/qcoreapplication.cpp:1821
#14 0x00007f4a46c90e27 in postEventSourceDispatch (s=0x55f81a1d2fc0) at kernel/qeventdispatcher_glib.cpp:276
#15 0x00007f4a4530ffed in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#16 0x00007f4a45310380 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#17 0x00007f4a45310423 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#18 0x00007f4a46c90bb5 in QEventDispatcherGlib::processEvents (this=0x55f81a1b1360, flags=...) at kernel/qeventdispatcher_glib.cpp:422
#19 0x00007f4a46c3a9db in QEventLoop::exec (this=this@entry=0x7ffe296ad0d0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:140
#20 0x00007f4a46c42706 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:120
#21 0x000055f81988e7e4 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/plasma-workspace-5.16.2-2.fc31.x86_64/shell/main.cpp:215
[Inferior 1 (process 3462) detached]
Version-Release number of selected component (if applicable):
The Plasma on X autologin splash screen freeze has happened several times after restarting sddm with two Fedora rawhide live images and an F30 installation. I saw the plasmashell segmentation fault once, and a plasmashell abort another time.
Steps to Reproduce:
1. boot into the Fedora Rawhide/31 KDE Plasma spin image Fedora-KDE-Live-x86_64-Rawhide-20190724.n.0.iso
2. sudo dnf install x*amd* kwin*way* pla*way*
3. log out of Plasma
4. switch to VT2 with ctrl-alt-f2 after Plasma splash screen freeze
5. sudo systemctl restart sddm
6. sudo systemctl stop sddm
7. startplasmacompositor &
The Plasma on X autologin stopped on the splash screen many times after logging out. plasmashell had a segmentation fault and abort during two of them.
Plasma would log in normally with no plasmashell crashes.
I reported this issue at https://bugs.kde.org/show_bug.cgi?id=410211
This bug appears to have been reported against 'rawhide' during the Fedora 31 development cycle.
Changing version to 31.