Bug 505938

Summary: Kwin dies, possibly due to missing icon or multiple config changes
Product: [Plasma] kwin Reporter: James J. Ramsey <jjramsey>
Component: generic-crashAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: crash CC: nate
Priority: NOR    
Version First Reported In: 6.4.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Tarball with multiple GDB backtraces

Description James J. Ramsey 2025-06-21 21:23:57 UTC 
Created attachment 182500 [details]
Tarball with multiple GDB backtraces

I've had two crashes with Kwin, the first of which unceremoniously took me right back to my display manager SDDM, and the second which Kwin seemed to recover from, at least in the sense that it didn't log me out and take me back to the display manager again. I think they're related, and possibly even related to #504657, but I'm not sure.

The first crash happened after I installed and loaded as much of the LyraB Global Theme (https://store.kde.org/p/1525522) that would work on KDE 6, so the Aurorae theme, the color scheme, the Kvantum theme, and the Lyra icon theme (lyra.tar.xz). The icon theme turned out to be *missing* some icons, and some of the icon files were actually broken symbolic links. In place of the LyraB Plasma Shell theme (which was for KDE 5), I loaded the Oxygen Plasma Shell theme. If I recall correctly -- and I'm not sure that I got everything straight -- the crash happened when I clicked on the tray icon for the Clipboard, which was one of the icons that was a broken link and showed up as a "blank" icon resembling a tiny sheet of paper. After I logged back in, there was about a minute delay before the desktop showed up again.

Unfortunately, I can't seem to reproduce this crash, not even with the conditions that seemed to precede it, so I'm guessing that there's more to in that just missing icons. Worse, kwin itself did not leave behind a core dump, though Plasma shell did. The backtrace from that is in a file named "coredumpctl-debug-plasmashell-Lyra.txt", within the attached tarball.

There's another file in that tarball, "coredumpctl-debug-plasmashell-prev.txt", which has another backtrace from a previous Plasma shell crash, one that did not take down Kwin. It happened before I started playing around with Lyra, but after I was trying out the Communality and Irixium global themes.

The second crash caused Plasma shell to restart and apparently crashed kwin as well, leaving behind a core file, but didn't force me back to SDDM. Instead, the window decorations disappeared from an instance of Konsole that I was running. I'm not sure quite what led to this crash, but I was again trying out different theming options: the "Candy" icons, the "Sweet" global themes, etc. There are four backtrace files from the core dumps associated with that: "coredumpctl-debug-plasmashell-next.txt", "coredumpctl-debug-systemsettings.txt", "coredumpctl-debug-Xwayland.txt", and "coredumpctl-debug-kwin_wayland.txt", all in the attached tarball.

I wish I could be more helpful here and provide something more than backtraces, but I don't have a clear idea what's triggering this.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.4.0
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.12.34-1-lts (64-bit)
Graphics Platform: Wayland
Processors: 12 × 12th Gen Intel® Core™ i5-12400
Memory: 32 GiB of RAM (31.2 GiB usable)
Graphics Processor: AMD Radeon RX 7800 XT
Comment 1 Vlad Zahorodnii 2025-06-23 07:36:14 UTC 
Thread 1 (Thread 0x7a82f8dcda40 (LWP 124753)):
+bt full
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
        tid = <optimized out>
        ret = 0
        pd = <optimized out>
        old_mask = {__val = {0}}
        ret = <optimized out>
#1  0x00007a82fe8a7813 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:89
#2  0x00007a82fe84ddc0 in __GI_raise (sig=6) at ../sysdeps/posix/raise.c:26
        ret = <optimized out>
#3  0x00007a8302189e97 in KCrash::defaultCrashHandler (sig=6) at /usr/src/debug/kcrash/kcrash-6.15.0/src/kcrash.cpp:605
        data = {<KCrash::MetadataWriter> = {_vptr.MetadataWriter = 0x7a830218f860 <vtable for KCrash::Metadata+16>}, argv = {_M_elems = {0x0, 0x7a830218d40c "--qtversion", 0x5c47d4632be0 "6.9.1", 0x7a830218d41f "--kdeframeworksversion", 0x7a830218d418 "6.15.0", 0x7a830218d457 "--platform", 0x7a830218d44f "wayland", 0x7a830218d488 "--appname", 0x5c47d4632cc0 "kwin_wayland", 0x7a830218d492 "--apppath", 0x5c47d4632d60 "/usr/bin", 0x7a830218d49f "--signal", 0x7fffcad51486 "6", 0x7a830218d4ad "--pid", 0x7fffcad51490 "124753", 0x7a830218d4b3 "--appversion", 0x5c47d4a18230 "6.4.0", 0x7a830218d4c0 "--programname", 0x5c47d4a181d0 "KWin", 0x7a830218d4ce "--bugaddress", 0x5c47d473c430 "submit@bugs.kde.org", 0x0 <repeats 17 times>}}, argc = 21, m_writer = 0x7fffcad51430}
        platformName = {d = {d = 0x7a82bc00d720, ptr = 0x7a82bc00d730 "wayland-org.kde.kwin.qpa", size = 24}, static _empty = 0 '\000'}
        about = 0x5c47d4a38110
        argv = 0x7fffcad514b8
        i = <optimized out>
        ini = {<KCrash::MetadataWriter> = {_vptr.MetadataWriter = 0x7a830218f890 <vtable for KCrash::MetadataINIWriter+16>}, writable = false, fd = 7}
        sigtxt = "6\000\201\025\325\312\377\177\000"
        pidtxt = "124753\000\000\000\000\000\000\000\000\000\000\002\000\000"
        argc = <optimized out>
        crashRecursionCounter = 2
#4  0x00007a82fe84def0 in <signal handler called> () at /usr/lib/libc.so.6
#5  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
        tid = <optimized out>
        ret = 0
        pd = <optimized out>
        old_mask = {__val = {101463584596048}}
        ret = <optimized out>
#6  0x00007a82fe8a7813 in __pthread_kill_internal (threadid=<optimized out>, signo=6) at pthread_kill.c:89
#7  0x00007a82fe84ddc0 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
        ret = <optimized out>
#8  0x00007a82fe83557a in __GI_abort () at abort.c:73
        act = {__sigaction_handler = {sa_handler = 0x7fffcad523f0, sa_sigaction = 0x7fffcad523f0}, sa_mask = {__val = {134703041385914, 101463597895312, 101463597895328, 64, 34, 140736596354048, 134703097041841, 134701893273984, 134702337857920, 134703097192448, 41943040, 140736596354112, 134703034804782, 134702939561288, 0, 0}}, sa_flags = 1479991808, sa_restorer = 0x7a82fe9c23a2}
#9  0x00007a82fe8365c9 in __libc_message_impl (fmt=fmt@entry=0x7a82fe9c239f "%s\n") at ../sysdeps/posix/libc_fatal.c:134
        ap = {{gp_offset = 16, fp_offset = 31362, overflow_arg_area = 0x7fffcad52570, reg_save_area = 0x7fffcad52500}}
        iov = {{iov_base = 0x7a82fe9c5618, iov_len = 31}, {iov_base = 0x7a82fe9c23a1, iov_len = 1}, {iov_base = 0x5c47d4b7a990, iov_len = 134703036197568}, {iov_base = 0x7fffcad524f0, iov_len = 134703034875390}, {iov_base = 0x60, iov_len = 134703036197568}, {iov_base = 0x7fffcad52520, iov_len = 9}, {iov_base = 0x7fffcad52540, iov_len = 134703034869907}}
        iovcnt = <optimized out>
        total = <optimized out>
        cp = <optimized out>
#10 0x00007a82fe8b1a35 in malloc_printerr (str=str@entry=0x7a82fe9c5618 "double free or corruption (out)") at malloc.c:5829
#11 0x00007a82fe8b3e70 in _int_free_merge_chunk (av=av@entry=0x7a82fe9f6ac0 <main_arena>, p=0x5c47d4ab4500, size=101463581240048) at malloc.c:4718
        nextchunk = 0xb88fa962eff0
        nextsize = <optimized out>
#12 0x00007a82fe8b3fb4 in _int_free_chunk (av=0x7a82fe9f6ac0 <main_arena>, p=<optimized out>, size=<optimized out>, have_lock=<optimized out>, have_lock@entry=0) at malloc.c:4667
        fb = <optimized out>
#13 0x00007a82fe8b6e52 in _int_free (av=<optimized out>, p=<optimized out>, have_lock=0) at malloc.c:4699
        size = <optimized out>
#14 __GI___libc_free (mem=<optimized out>) at malloc.c:3476
        ar_ptr = <optimized out>
        p = <optimized out>
        err = 9
#15 0x00007a82f518ea53 in si_destroy_screen () at ../mesa-25.1.4/src/gallium/drivers/radeonsi/si_pipe.c:1009
#16 0x00007a82f483d577 in dri_release_screen () at ../mesa-25.1.4/src/gallium/frontends/dri/dri_screen.c:565
#17 0x00007a82f483d5d5 in dri_destroy_screen () at ../mesa-25.1.4/src/gallium/frontends/dri/dri_screen.c:580
#18 0x00007a83023cc4be in dri_destroy () at ../mesa-25.1.4/src/gbm/backends/dri/gbm_dri.c:1157
#19 0x00007a82fe742104 in _gbm_device_destroy () at ../mesa-25.1.4/src/gbm/main/backend.c:172
#20 0x00007a830198eb6a in KWin::DrmDevice::~DrmDevice (this=0x5c47d4c09620, this=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/core/drmdevice.cpp:35
#21 0x00007a8301c8a579 in std::default_delete<KWin::DrmDevice>::operator() (this=<optimized out>, __ptr=0x5c47d4c09620) at /usr/include/c++/15.1.1/bits/unique_ptr.h:87
#22 std::default_delete<KWin::DrmDevice>::operator() (this=<optimized out>, __ptr=0x5c47d4c09620, this=<optimized out>, __ptr=<optimized out>) at /usr/include/c++/15.1.1/bits/unique_ptr.h:87
#23 std::unique_ptr<KWin::DrmDevice, std::default_delete<KWin::DrmDevice> >::~unique_ptr (this=0x5c47d4c1bfd8, this=<optimized out>) at /usr/include/c++/15.1.1/bits/unique_ptr.h:399
        __ptr = @0x5c47d4c1bfd8: 0x5c47d4c09620
        __ptr = <optimized out>
#24 KWin::DrmGpu::~DrmGpu (this=0x5c47d4c1bfc0, this=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/backends/drm/drm_gpu.cpp:119
#25 0x00007a8301c64405 in KWin::DrmGpu::~DrmGpu (this=0x5c47d4c1bfc0, this=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/backends/drm/drm_gpu.cpp:110
#26 std::default_delete<KWin::DrmGpu>::operator() (this=<optimized out>, __ptr=0x5c47d4c1bfc0) at /usr/include/c++/15.1.1/bits/unique_ptr.h:93
#27 std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> >::~unique_ptr (this=0x5c47d4c2c740, this=<optimized out>) at /usr/include/c++/15.1.1/bits/unique_ptr.h:399
        __ptr = @0x5c47d4c2c740: 0x5c47d4c1bfc0
        __ptr = <optimized out>
#28 std::destroy_at<std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> > > (__location=0x5c47d4c2c740) at /usr/include/c++/15.1.1/bits/stl_construct.h:88
#29 std::_Destroy<std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> > > (__pointer=0x5c47d4c2c740) at /usr/include/c++/15.1.1/bits/stl_construct.h:164
#30 std::_Destroy<std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> >*> (__first=0x5c47d4c2c740, __last=0x5c47d4c2c748) at /usr/include/c++/15.1.1/bits/stl_construct.h:212
#31 std::_Destroy<std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> >*, std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> > > (__first=<optimized out>, __last=0x5c47d4c2c748) at /usr/include/c++/15.1.1/bits/alloc_traits.h:1045
#32 std::vector<std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> >, std::allocator<std::unique_ptr<KWin::DrmGpu, std::default_delete<KWin::DrmGpu> > > >::~vector (this=0x5c47d484abe0, this=<optimized out>) at /usr/include/c++/15.1.1/bits/stl_vector.h:802
#33 KWin::DrmBackend::~DrmBackend (this=0x5c47d484ab60, this=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/backends/drm/drm_backend.cpp:80
#34 0x00007a8301c64616 in KWin::DrmBackend::~DrmBackend (this=0x5c47d484ab60, this=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/backends/drm/drm_backend.cpp:80
#35 0x00007a8301a905f0 in KWin::Application::~Application (this=0x7fffcad52cf0, this=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/main.cpp:140
#36 0x00005c47c4c69032 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/kwin/kwin-6.4.0/src/main_wayland.cpp:636
        environment = {d = {d = {ptr = 0x5c47d46427f0}}}
        a = {<KWin::Application> = {<QApplication> = {<QGuiApplication> = {<QCoreApplication> = {<QObject> = {_vptr.QObject = 0x7a8301fd6668 <vtable for KWin::Application+16>, static staticMetaObject = {d = {superdata = {direct = 0x0}, stringdata = 0x7a82ff2cda70 <_ZN7QObject32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_125qt_meta_tag_ZN7QObjectE_tEEE.lto_priv.0+272>, data = 0x7a82ff2cd960 <_ZN7QObject32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_125qt_meta_tag_ZN7QObjectE_tEEE.lto_priv.0>, static_metacall = 0x7a82fefce080 <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, metaTypes = 0x7a82ff4114c0 <_ZN7QObject36qt_staticMetaObjectRelocatingContentIN12_GLOBAL__N_125qt_meta_tag_ZN7QObjectE_tEEE.lto_priv.0>, extradata = 0x0}}, d_ptr = {d = 0x5c47d4646570}}, static staticMetaObject = {d = {superdata = {direct = 0x7a82ff411540 <QObject::staticMetaObject>}, stringdata = 0x7a82ff2cd028 <_ZN16QCoreApplication32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_135qt_meta_tag_ZN16QCoreApplicationE_tEEE.lto_priv.0+392>, data = 0x7a82ff2ccea0 <_ZN16QCoreApplication32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_135qt_meta_tag_ZN16QCoreApplicationE_tEEE.lto_priv.0>, static_metacall = 0x7a82fef722a0 <QCoreApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, metaTypes = 0x7a82ff411020 <_ZN16QCoreApplication36qt_staticMetaObjectRelocatingContentIN12_GLOBAL__N_135qt_meta_tag_ZN16QCoreApplicationE_tEEE.lto_priv.0>, extradata = 0x0}}, static self = 0x7fffcad52cf0}, static staticMetaObject = {d = {superdata = {direct = 0x7a82ff4110a0 <QCoreApplication::staticMetaObject>}, stringdata = 0x7a82ffdb0490 <_ZN15QGuiApplication32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_134qt_meta_tag_ZN15QGuiApplicationE_tEEE.lto_priv.0+752>, data = 0x7a82ffdb01a0 <_ZN15QGuiApplication32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_134qt_meta_tag_ZN15QGuiApplicationE_tEEE.lto_priv.0>, static_metacall = 0x7a82ff7ae5f0 <QGuiApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, metaTypes = 0x7a82ffecca00 <_ZN15QGuiApplication36qt_staticMetaObjectRelocatingContentIN12_GLOBAL__N_134qt_meta_tag_ZN15QGuiApplicationE_tEEE.lto_priv.0>, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = {direct = 0x7a82ffecd300 <QGuiApplication::staticMetaObject>}, stringdata = 0x7a83007c7548 <_ZN12QApplication32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_131qt_meta_tag_ZN12QApplicationE_tEEE.lto_priv.0+392>, data = 0x7a83007c73c0 <_ZN12QApplication32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_131qt_meta_tag_ZN12QApplicationE_tEEE.lto_priv.0>, static_metacall = 0x7a83003046b0 <QApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, metaTypes = 0x7a830090b5c0 <_ZN12QApplication36qt_staticMetaObjectRelocatingContentIN12_GLOBAL__N_131qt_meta_tag_ZN12QApplicationE_tEEE.lto_priv.0>, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = {direct = 0x7a830091a3e0 <QApplication::staticMetaObject>}, stringdata = 0x7a8301eaa2ec <_ZN4KWin11Application32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_135qt_meta_tag_ZN4KWin11ApplicationE_tEEE.lto_priv.0+300>, data = 0x7a8301eaa1c0 <_ZN4KWin11Application32qt_staticMetaObjectStaticContentIN12_GLOBAL__N_135qt_meta_tag_ZN4KWin11ApplicationE_tEEE.lto_priv.0>, static_metacall = 0x7a8301a8ee70 <KWin::Application::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, metaTypes = 0x7a8301fca960 <_ZN4KWin11Application36qt_staticMetaObjectRelocatingContentIN12_GLOBAL__N_135qt_meta_tag_ZN4KWin11ApplicationE_tEEE.lto_priv.0>, extradata = 0x0}}, static crashes = 0, m_eventFilters = {<QListSpecialMethods<QPointer<KWin::X11EventFilterContainer> >> = {<QListSpecialMethodsBase<QPointer<KWin::X11EventFilterContainer> >> = {<No data fields>}, <No data fields>}, d = {d = 0x5c47d5f7ca80, ptr = 0x5c47d5f7cab0, size = 0}}, m_genericEventFilters = {<QListSpecialMethods<QPointer<KWin::X11EventFilterContainer> >> = {<QListSpecialMethodsBase<QPointer<KWin::X11EventFilterContainer> >> = {<No data fields>}, <No data fields>}, d = {d = 0x0, ptr = 0x0, size = 0}}, m_eventFilter = std::unique_ptr<class KWin::XcbEventFilter> = {get() = 0x5c47d49eb790}, m_followLocale1 = false, m_configLock = false, m_initiallyLocked = false, m_supportsLockScreen = true, m_supportsGlobalShortcuts = true, m_config = {d = {ptr = 0x5c47d473c0e0}}, m_kxkbConfig = {d = {ptr = 0x5c47d4a14bc0}}, m_inputConfig = {d = {ptr = 0x5c47d4a14be0}}, m_kdeglobals = {d = {ptr = 0x5c47d473c4f0}}, m_x11Time = 9897262, m_rootWindow = 0, m_compositeWindow = 0, m_connection = 0x0, m_useKActivities = true, m_session = std::unique_ptr<class KWin::Session> = {get() = 0x5c47d473c480}, m_outputBackend = std::unique_ptr<class KWin::OutputBackend> = {get() = 0x0}, m_terminating = true, m_xwaylandScale = 1, m_processEnvironment = {d = {d = {ptr = 0x5c47d5fa4c70}}}, m_pluginManager = std::unique_ptr<class KWin::PluginManager> = {get() = 0x0}, m_inputMethod = std::unique_ptr<class KWin::InputMethod> = {get() = 0x0}, m_colorManager = std::unique_ptr<class KWin::ColorManager> = {get() = 0x0}, m_tabletModeManager = std::unique_ptr<class KWin::TabletModeManager> = {get() = 0x5c47d4dc42c0}, m_screenLockerWatcher = std::unique_ptr<class KWin::ScreenLockerWatcher> = {get() = 0x5c47d4c75070}}, static staticMetaObject = {d = {superdata = {direct = 0x7a8301fcacc0 <KWin::Application::staticMetaObject>}, stringdata = 0x5c47c4d4dffc <KWin::ApplicationWayland::qt_staticMetaObjectStaticContent<(anonymous namespace)::qt_meta_tag_ZN4KWin18ApplicationWaylandE_t>+60>, data = 0x5c47c4d4dfc0 <KWin::ApplicationWayland::qt_staticMetaObjectStaticContent<(anonymous namespace)::qt_meta_tag_ZN4KWin18ApplicationWaylandE_t>>, static_metacall = 0x5c47c4c6f3b0 <KWin::ApplicationWayland::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, metaTypes = 0x5c47c4d80970 <KWin::ApplicationWayland::qt_staticMetaObjectRelocatingContent<(anonymous namespace)::qt_meta_tag_ZN4KWin18ApplicationWaylandE_t>>, extradata = 0x0}}, m_applicationsToStart = {<QListSpecialMethods<QString>> = {<QListSpecialMethodsBase<QString>> = {<No data fields>}, <No data fields>}, d = {d = 0x0, ptr = 0x0, size = 0}}, m_inputMethodServerToStart = {d = {d = 0x0, ptr = 0x0, size = 0}, static _empty = 0 u'\000'}, m_sessionArgument = {d = {d = 0x0, ptr = 0x0, size = 0}, static _empty = 0 u'\000'}, m_startXWayland = true, m_xwayland = std::unique_ptr<class KWin::Xwl::Xwayland> = {get() = 0x0}, m_xwaylandListenFds = {<QListSpecialMethods<int>> = {<QListSpecialMethodsBase<int>> = {<No data fields>}, <No data fields>}, d = {d = 0x5c47d4a2d560, ptr = 0x5c47d4a2d570, size = 2}}, m_xwaylandDisplay = {d = {d = 0x5c47d4a41140, ptr = 0x5c47d4a41150 u":0", size = 2}, static _empty = 0 u'\000'}, m_xwaylandXauthority = {d = {d = 0x5c47d4737da0, ptr = 0x5c47d4737db0 u"/run/user/1000/xauth_QoYgoP", size = 27}, static _empty = 0 u'\000'}, m_xwaylandExtraEnvironment = {d = {d = {ptr = 0x0}}}, m_xwaylandFds = std::vector of length 0, capacity 0, m_settingsWatcher = {value = {ptr = 0x5c47d4a1d120}, d = 0x5c47d4a347d0}}
        xwaylandOption = {d = {d = {ptr = 0x5c47d4a39560}}}
        waylandSocketOption = {d = {d = {ptr = 0x5c47d4a395e0}}}
        x11DisplayOption = {d = {d = {ptr = 0x5c47d4a39770}}}
        waylandDisplayOption = {d = {d = {ptr = 0x5c47d4a39900}}}
        virtualFbOption = {d = {d = {ptr = 0x5c47d4a39980}}}
        widthOption = {d = {d = {ptr = 0x5c47d4a39a00}}}
        heightOption = {d = {d = {ptr = 0x5c47d4a3f3e0}}}
        fullscreenOption = {d = {d = {ptr = 0x5c47d4a3f4b0}}}
        scaleOption = {d = {d = {ptr = 0x5c47d4a3f580}}}
        outputCountOption = {d = {d = {ptr = 0x5c47d4a3f7a0}}}
        waylandSocketFdOption = {d = {d = {ptr = 0x5c47d4a3f870}}}
        xwaylandListenFdOption = {d = {d = {ptr = 0x5c47d4a31770}}}
        xwaylandDisplayOption = {d = {d = {ptr = 0x5c47d4a31ac0}}}
        xwaylandXAuthorityOption = {d = {d = {ptr = 0x5c47d4a31b40}}}
        replaceOption = {d = {d = {ptr = 0x5c47d4a31d20}}}
        drmOption = {d = {d = {ptr = 0x5c47d4a38a30}}}
        locale1Option = {d = {d = {ptr = 0x5c47d4a38c10}}}
        parser = {d = 0x5c47d4864f20}
        inputMethodOption = {d = {d = {ptr = 0x5c47d4a1dda0}}}
        screenLockerOption = {d = {d = {ptr = 0x5c47d4a1df00}}}
        noScreenLockerOption = {d = {d = {ptr = 0x5c47d4a2a590}}}
        noGlobalShortcutsOption = {d = {d = {ptr = 0x5c47d4a2a810}}}
        noActivitiesOption = {d = {d = {ptr = 0x5c47d4a2a890}}}
        exitWithSessionOption = {d = {d = {ptr = 0x5c47d4a2aa70}}}
        backendType = <optimized out>
        pluginName = {d = {d = 0x0, ptr = 0x0, size = 0}, static _empty = 0 u'\000'}
        initialWindowSize = {wd = <optimized out>, ht = <optimized out>}
        outputCount = <optimized out>
        outputScale = <optimized out>
        ok = true
        width = <optimized out>
        height = <optimized out>
        scale = <optimized out>
        fullscreen = <optimized out>
        count = <optimized out>
        server = <optimized out>
        socketName = {d = {d = 0x5c47d4a29480, ptr = 0x5c47d4a29490 u"wayland-0", size = 9}, static _empty = 0 u'\000'}
Comment 2 Vlad Zahorodnii 2025-06-23 07:36:58 UTC 
Looks like a bug in Mesa.
Comment 3 James J. Ramsey 2025-06-23 10:19:01 UTC 
I wonder why I haven't seen any other compositors trigger this. I've used Hyprland, Sway, and even a git version of Labwc. Nothing like this.
Comment 4 James J. Ramsey 2025-06-23 10:35:24 UTC 
Also, I don't recall seeing a similar problem last year with KDE.

Do you think using the LyraB or LyraP Aurorae themes might be a trigger, since they're fairly fancy?
Comment 5 James J. Ramsey 2025-06-24 11:27:09 UTC 
A funny thing happened when I attached gdb to a running kwin_wayland -- following instructions at https://community.kde.org/KWin/Debugging#Debug_KWin_with_GDB -- in a virtual terminal. Again, I got kicked back to SDDM while running a KDE session, but when I switched to the virtual terminal where gdb was running to see if I could get a backtrace, kwin_wayland was still apparently running, and I could switch to the virtual terminal that still had the running KDE session.

I'm not sure if that's what really happened the two times that KWin apparently crashed and "unceremoniously took me right back to my display manager SDDM" without leaving a core dump, but it would explain why there was no core dump. (I say two times, because after I made this bug report, I got taken back to SDDM a second time. This is separate from the crash that *did* leave a core dump.)
Comment 6 James J. Ramsey 2025-06-26 01:39:20 UTC 
I encountered the sudden virtual terminal switching problem even without GDB. Looks like this isn't actually a *crashing* problem per se, and I don't even know if it's a Kwin problem. Reporting the bug properly now, and reporting this as a duplicate of it.

*** This bug has been marked as a duplicate of bug 506193 ***