When I use the scroll bar in kdevelop to scroll through some source code and I release the scroll bar with the mouse, kwin wayland will crash and you are back to the login screen (SDDM). Login with SDDM allows to open a new session, but as there are many left overs from the previous session you need to reboot. The crash happens on Intel and AMD hardware. This seems like a regression in Plasma 5.20 Beta, as I've never seen this before. STEPS TO REPRODUCE 1. Open a file with a lot of code/text in kdevelop 2. Scroll with the scroll bar OBSERVED RESULT - Kwin crashes EXPECTED RESULT - Noting will crash Operating System: Arch Linux KDE Plasma Version: 5.19.90 KDE Frameworks Version: 5.74.0 Qt Version: 5.15.1 Kernel Version: 5.8.10-arch1-1 OS Type: 64-bit Processors: 24 × AMD Ryzen 9 3900X 12-Core Processor Memory: 31.4 GiB of RAM Graphics Processor: AMD Radeon VII
Can you get a backtrace of kwin please. https://www.proli.net/2020/04/03/developing-kwin-wayland/
Well, I will try to provide the requested output but as I'm not a developer I'm not sure how helpful I can be here. First attempt on Arch Linux: Thread 1 "kwin_wayland" received signal SIGSEGV, Segmentation fault. 0x00007f73ca295064 in KWaylandServer::BufferInterface::unref() () from /usr/lib/libKWaylandServer.so.5 (gdb) bt #0 0x00007f73ca295064 in KWaylandServer::BufferInterface::unref() () at /usr/lib/libKWaylandServer.so.5 #1 0x00007f73ca2cf2cd in () at /usr/lib/libKWaylandServer.so.5 #2 0x00007f73ca2d024d in KWaylandServer::ShadowInterface::~ShadowInterface() () at /usr/lib/libKWaylandServer.so.5 #3 0x00007f73ca2d02da in () at /usr/lib/libKWaylandServer.so.5 #4 0x00007f73ca2ff578 in () at /usr/lib/libKWaylandServer.so.5 #5 0x00007f73c7408e90 in () at /usr/lib/libwayland-server.so.0 #6 0x00007f73c7408f11 in wl_resource_destroy () at /usr/lib/libwayland-server.so.0 #7 0x00007f73c6027a8d in () at /usr/lib/libffi.so.7 #8 0x00007f73c602701b in () at /usr/lib/libffi.so.7 #9 0x00007f73c740cf62 in () at /usr/lib/libwayland-server.so.0 #10 0x00007f73c74092dc in () at /usr/lib/libwayland-server.so.0 #11 0x00007f73c740afaa in wl_event_loop_dispatch () at /usr/lib/libwayland-server.so.0 #12 0x00007f73ca29ba30 in KWaylandServer::Display::Private::dispatch() () at /usr/lib/libKWaylandServer.so.5 #13 0x00007f73c9085036 in () at /usr/lib/libQt5Core.so.5 #14 0x00007f73c90885a0 in QSocketNotifier::activated(QSocketDescriptor, QSocketNotifier::Type, QSocketNotifier::QPrivateSignal) () at /usr/lib/libQt5Core.so.5 #15 0x00007f73c9088dad in QSocketNotifier::event(QEvent*) () at /usr/lib/libQt5Core.so.5 #16 0x00007f73c9b15752 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5 #17 0x00007f73c904dcda in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5 #18 0x00007f73c90a3c34 in QEventDispatcherUNIXPrivate::activateSocketNotifiers() () at /usr/lib/libQt5Core.so.5 #19 0x00007f73c90a40b5 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5 #20 0x00007f73c34c391e in () at /usr/lib/qt/plugins/platforms/KWinQpaPlugin.so #21 0x00007f73c904c65c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5 #22 0x00007f73c9054af4 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5 #23 0x0000557fdfeb484e in () #24 0x00007f73c88c1152 in __libc_start_main () at /usr/lib/libc.so.6 #25 0x0000557fdfeb50de in _start () As it is related to kwayland, I compiled it again with debug symbols: Thread 1 "kwin_wayland" received signal SIGSEGV, Segmentation fault. 0x00007f19c7e35995 in KWaylandServer::BufferInterface::unref (this=0x55e8209d18b0) at /usr/include/qt/QtCore/qscopedpointer.h:116 116 T *operator->() const noexcept (gdb) bt #0 0x00007f19c7e35995 in KWaylandServer::BufferInterface::unref() (this=0x55e8209d18b0) at /usr/include/qt/QtCore/qscopedpointer.h:116 #1 0x00007f19c7e7730d in KWaylandServer::ShadowInterfacePrivate::~ShadowInterfacePrivate() (this=0x55e820a51730, __in_chrg=<optimized out>) at /usr/src/debug/kwayland-server/src/server/shadow_interface.cpp:337 #2 0x00007f19c7e77c2d in KWaylandServer::ShadowInterfacePrivate::~ShadowInterfacePrivate() (this=0x55e820a51730, __in_chrg=<optimized out>) at /usr/src/debug/kwayland-server/src/server/shadow_interface.cpp:331 #3 QScopedPointerDeleter<KWaylandServer::ShadowInterfacePrivate>::cleanup(KWaylandServer::ShadowInterfacePrivate*) (pointer=0x55e820a51730) at /usr/include/qt/QtCore/qscopedpointer.h:60 #4 QScopedPointer<KWaylandServer::ShadowInterfacePrivate, QScopedPointerDeleter<KWaylandServer::ShadowInterfacePrivate> >::~QScopedPointer() (this=0x55e82092b450, __in_chrg=<optimized out>) at /usr/include/qt/QtCore/qscopedpointer.h:107 #5 KWaylandServer::ShadowInterface::~ShadowInterface() (this=0x55e82092b440, __in_chrg=<optimized out>) at /usr/src/debug/kwayland-server/src/server/shadow_interface.cpp:354 #6 0x00007f19c7e77cba in KWaylandServer::ShadowInterface::~ShadowInterface() (this=0x55e82092b440, __in_chrg=<optimized out>) at /usr/src/debug/kwayland-server/src/server/shadow_interface.cpp:354 #7 KWaylandServer::ShadowInterfacePrivate::org_kde_kwin_shadow_destroy_resource(QtWaylandServer::org_kde_kwin_shadow::Resource*) (this=<optimized out>, resource=<optimized out>) at /usr/src/debug/kwayland-server/src/server/shadow_interface.cpp:246 #8 0x00007f19c7eab250 in QtWaylandServer::org_kde_kwin_shadow::destroy_func(wl_resource*) (client_resource=<optimized out>) at /usr/include/qt/QtCore/qmap.h:212 #9 0x00007f19c4fa6e90 in () at /usr/lib/libwayland-server.so.0 #10 0x00007f19c4fa6f11 in wl_resource_destroy () at /usr/lib/libwayland-server.so.0 #11 0x00007f19c3bc5a8d in () at /usr/lib/libffi.so.7 #12 0x00007f19c3bc501b in () at /usr/lib/libffi.so.7 #13 0x00007f19c4faaf62 in () at /usr/lib/libwayland-server.so.0 #14 0x00007f19c4fa72dc in () at /usr/lib/libwayland-server.so.0 #15 0x00007f19c4fa8faa in wl_event_loop_dispatch () at /usr/lib/libwayland-server.so.0 #16 0x00007f19c7e3c9e0 in KWaylandServer::Display::Private::dispatch() (this=<optimized out>) at /usr/src/debug/kwayland-server/src/server/display.cpp:135 #17 0x00007f19c6c23036 in () at /usr/lib/libQt5Core.so.5 #18 0x00007f19c6c265a0 in QSocketNotifier::activated(QSocketDescriptor, QSocketNotifier::Type, QSocketNotifier::QPrivateSignal) () at /usr/lib/libQt5Core.so.5 #19 0x00007f19c6c26dad in QSocketNotifier::event(QEvent*) () at /usr/lib/libQt5Core.so.5 #20 0x00007f19c76b3752 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5 #21 0x00007f19c6bebcda in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5 #22 0x00007f19c6c41c34 in QEventDispatcherUNIXPrivate::activateSocketNotifiers() () at /usr/lib/libQt5Core.so.5 #23 0x00007f19c6c420b5 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5 #24 0x00007f19c106191e in () at /usr/lib/qt/plugins/platforms/KWinQpaPlugin.so #25 0x00007f19c6bea65c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5 #26 0x00007f19c6bf2af4 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5 #27 0x000055e81d73884e in () #28 0x00007f19c645f152 in __libc_start_main () at /usr/lib/libc.so.6 #29 0x000055e81d7390de in _start () I've replaced now qt5-base 5.15.1 with qt5-base-debug 5.15.0 (which is the latest one available from the Arch Linux debug repository)... but now I can't login to Plasma anymore :-( I will try to compile qt5-base now as well, but it may take some time on my notebook.
That's perfect as-is. thanks
*** This bug has been marked as a duplicate of bug 425233 ***