At least I think it is Qt 5.5. I am using the qscreen kscreen backend on Wayland, but it still crashes with xrandr on xcb...

If I try it with the fake screen backend, it appears to hang, but that's probably a different issue?

Reproducible: Always




Stack trace of plasmashell and qscreen crash

Starting program: /opt/bin/plasmashell 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[New Thread 0xae2c0b40 (LWP 3193)]
[New Thread 0xabaf9b40 (LWP 3208)]
[New Thread 0xa2580b40 (LWP 3245)]
[New Thread 0xa366db40 (LWP 3243)]
[New Thread 0xa09ffb40 (LWP 3289)]
[New Thread 0xa4751b40 (LWP 3242)]
[New Thread 0xa5835b40 (LWP 3241)]
[New Thread 0xa6919b40 (LWP 3240)]
[New Thread 0xa79fdb40 (LWP 3239)]
[New Thread 0xa8ac1b40 (LWP 3238)]
[New Thread 0xa9c05b40 (LWP 3237)]
[New Thread 0xaa9efb40 (LWP 3235)]
[New Thread 0xb2243b40 (LWP 3141)]

Program received signal SIGABRT, Aborted.
0xb7fdbbe0 in __kernel_vsyscall ()
#0  0xb7fdbbe0 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb50df057 in __GI_raise (sig=6) at ../sysdeps/unix/sysv/linux/raise.c:55
        resultvar = <optimized out>
        resultvar = <optimized out>
        pid = -1255759872
        selftid = 3052
#2  0xb50e0699 in __GI_abort () at abort.c:89
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x1, sa_sigaction = 0x1}, 
          sa_mask = {__val = {146749120, 3051473152, 3086898320, 3087003648, 
              3040359928, 2991422432, 3053576888, 3086918165, 3053577328, 
              2991422432, 1, 5, 0, 3221218792, 2678063200, 145644696, 
              3221218712, 3040455608, 3046490340, 70, 3221218632, 3040792950, 
              3044157344, 3037434164, 3221218632, 3040873674, 3086917979, 
              3046490100, 3221219304, 3221219292, 3221218664, 3086944144}}, 
          sa_flags = -1073748592, sa_restorer = 0xb50e0550 <__GI_abort>}
        sigs = {__val = {32, 0 <repeats 31 times>}}
#3  0xb5409ce0 in qt_message_fatal (context=..., message=...)
    at /srcbuild/qtbase/src/corelib/global/qlogging.cpp:1575
No locals.
#4  0xb5405f36 in QMessageLogger::fatal (this=0xbfffe5e8, 
    msg=0xb571effc "ASSERT: \"%s\" in file %s, line %d")
    at /srcbuild/qtbase/src/corelib/global/qlogging.cpp:777
        message = {static null = {<No data fields>}, d = 0x8b23598}
        ap = 0xbfffe5b8 "5)\352\266\271+\352\266\357\004"
#5  0xb53ff98e in qt_assert (assertion=0xb6ea2935 "o", 
    file=0xb6ea2bb9 "jsruntime/qv4engine.cpp", line=1263)
    at /srcbuild/qtbase/src/corelib/global/qglobal.cpp:2894
        __PRETTY_FUNCTION__ = "void qt_assert(const char*, const char*, int)"
#6  0xb6c2792c in toVariant (e=0x86df400, value=..., typeHint=-1, 
    createJSValueForObjects=true, visitedObjects=0x0)
    at jsruntime/qv4engine.cpp:1263
        scope = {engine = 0x86df400, mark = 0x9fa00008, size = 1}
        o = {ptr = 0x9fa00008}
#7  0xb6c27146 in QV4::ExecutionEngine::toVariant (this=0x86df400, value=..., 
    typeHint=-1, createJSValueForObjects=true) at jsruntime/qv4engine.cpp:1178
No locals.
#8  0xb6d2f536 in QQmlExpressionPrivate::value (this=0x872eed0, 
    isUndefined=0x0) at qml/qqmlexpression.cpp:281
        scope = {engine = 0x86df400, mark = 0x9fa00000, size = 1}
        result = {ptr = 0x9fa00000}
        q = 0xbfffe7e0
        __PRETTY_FUNCTION__ = "QVariant QQmlExpressionPrivate::value(bool*)"
        ep = 0x874a020
        rv = {d = {data = {c = 0 '\000', uc = 0 '\000', s = 0, sc = 0 '\000', 
              us = 0, i = 0, u = 0, l = 0, ul = 0, b = false, 
              d = -1.1827624137658888e-52, f = 0, 
              real = -1.1827624137658888e-52, ll = -5393438510898216960, 
              ull = 13053305562811334656, o = 0x0, ptr = 0x0, shared = 0x0}, 
            type = 0, is_shared = 0, is_null = 1}}
#9  0xb6d2f5dd in QQmlExpression::evaluate (this=0xbfffe7e0, 
    valueIsUndefined=0x0) at qml/qqmlexpression.cpp:301
        d = 0x872eed0
#10 0xa9c2beea in WallpaperInterface::loadFinished() ()
   from /opt/lib/i386-linux-gnu/plugins/plasma_appletscript_declarative.so
No symbol table info available.
#11 0xa9c2d0ab in QtPrivate::QSlotObject<void (WallpaperInterface::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) () from /opt/lib/i386-linux-gnu/plugins/plasma_appletscript_declarative.so
No symbol table info available.
#12 0xb563f804 in QtPrivate::QSlotObjectBase::call (this=0x87354b8, 
    r=0x8697098, a=0xbfffe898)
    at ../../include/QtCore/../../../src/corelib/kernel/qobject_impl.h:124
No locals.
#13 0xb563ca24 in QMetaObject::activate (sender=0x86e9d88, signalOffset=3, 
    local_signal_index=0, argv=0x0)
    at /srcbuild/qtbase/src/corelib/kernel/qobject.cpp:3703
        obj = {d = 0x87354b8}
        receiverInSameThread = true
        sw = {receiver = 0x8697098, previousSender = 0x0, currentSender = {
            sender = 0x86e9d88, signal = 3, ref = 1}, switched = true}
        callFunction = 0x87354b8
        receiver = 0x8697098
        method_relative = 108
        c = 0x8733a10
        last = 0x8733a10
        locker = {val = 3046506612}
        connectionLists = {connectionLists = 0x87354d0}
        list = 0x8735510
        signal_index = 3
        empty_argv = {0x0}
        currentThreadId = 0xb24d2740
        __PRETTY_FUNCTION__ = "static void QMetaObject::activate(QObject*, int, int, void**)"
#14 0xb563c42d in QMetaObject::activate (sender=0x86e9d88, 
    m=0xb7501d38 <KDeclarative::QmlObject::staticMetaObject>, 
    local_signal_index=0, argv=0x0)
    at /srcbuild/qtbase/src/corelib/kernel/qobject.cpp:3583
No locals.
#15 0xb74e60c2 in KDeclarative::QmlObject::finished() ()
   from /opt/lib/i386-linux-gnu/libKF5Declarative.so.5
No symbol table info available.
#16 0xb74e7a40 in KDeclarative::QmlObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () from /opt/lib/i386-linux-gnu/libKF5Declarative.so.5
No symbol table info available.
#17 0xb56351a6 in QMetaCallEvent::placeMetaCall (this=0x85fffc0, 
    object=0x86e9d88) at /srcbuild/qtbase/src/corelib/kernel/qobject.cpp:486
No locals.
#18 0xb563621e in QObject::event (this=0x86e9d88, e=0x85fffc0)
    at /srcbuild/qtbase/src/corelib/kernel/qobject.cpp:1246
        mce = 0x85fffc0
        sw = {receiver = 0x86e9d88, previousSender = 0x0, currentSender = {
            sender = 0x0, signal = -1, ref = 1}, switched = true}
#19 0xb611c254 in QApplicationPrivate::notify_helper (this=0x8105d20, 
    receiver=0x86e9d88, e=0x85fffc0)
    at /srcbuild/qtbase/src/widgets/kernel/qapplication.cpp:3713
        consumed = true
#20 0xb6119715 in QApplication::notify (this=0xbffff0f8, receiver=0x86e9d88, 
    e=0x85fffc0) at /srcbuild/qtbase/src/widgets/kernel/qapplication.cpp:3157
        d = 0x8105d20
        __PRETTY_FUNCTION__ = "virtual bool QApplication::notify(QObject*, QEvent*)"
        res = false
#21 0xb55feb29 in QCoreApplication::notifyInternal (this=0xbffff0f8, 
    receiver=0x86e9d88, event=0x85fffc0)
    at /srcbuild/qtbase/src/corelib/kernel/qcoreapplication.cpp:963
        threadData = 0x81011c0
        loopLevelCounter = {threadData = 0x81011c0}
        result = false
        cbdata = {0x86e9d88, 0x85fffc0, 0xbfffed13}
        d = 0x8696338
#22 0xb5602baa in QCoreApplication::sendEvent (receiver=0x86e9d88, 
    event=0x85fffc0)
    at ../../include/QtCore/../../../src/corelib/kernel/qcoreapplication.h:228
No locals.
#23 0xb55ffe4d in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, 
    event_type=0, data=0x81011c0)
    at /srcbuild/qtbase/src/corelib/kernel/qcoreapplication.cpp:1580
        e = 0x85fffc0
        pe = @0x82d0308: {receiver = 0x86e9d88, event = 0x0, priority = 0}
        r = 0x86e9d88
        unlocker = {m = @0xbfffed8c}
        event_deleter = {d = 0x85fffc0}
        __PRETTY_FUNCTION__ = "static void QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*)"
        locker = {val = 135270876}
        startOffset = 0
        i = @0x81011d4: 5
        cleanup = {receiver = 0x0, event_type = 0, data = 0x81011c0, 
          exceptionCaught = true}
#24 0xb55ff8d7 in QCoreApplication::sendPostedEvents (receiver=0x0, 
    event_type=0)
    at /srcbuild/qtbase/src/corelib/kernel/qcoreapplication.cpp:1438
        data = 0x81011c0
#25 0xb5674e94 in postEventSourceDispatch (s=0x81266c0)
    at /srcbuild/qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:271
        source = 0x81266c0
#26 0xb443ac84 in g_main_dispatch (context=<optimized out>) at gmain.c:3122
        user_data = 0x0
        callback = 0x0
        cb_funcs = 0x6
        source = 0x81266c0
        current = 0x8131008
        i = 6
#27 g_main_context_dispatch (context=0x0) at gmain.c:3737
No locals.
#28 0xb443afa9 in g_main_context_iterate (context=0xb1903000, block=6, 
    block@entry=1, dispatch=1, self=<optimized out>) at gmain.c:3808
        max_priority = 0
        timeout = 0
        some_ready = 1
        fds = 0x1
#29 0xb443b076 in g_main_context_iteration (context=0xb1903000, may_block=1)
    at gmain.c:3869
        retval = <optimized out>
#30 0xb56755fc in QEventDispatcherGlib::processEvents (this=0x8123bb8, 
    flags=...)
    at /srcbuild/qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:418
        d = 0x81237f8
        canWait = true
        savedFlags = {i = 0}
        result = 95
#31 0xb245d197 in QPAEventDispatcherGlib::processEvents (this=0x8123bb8, 
    flags=...)
    at /srcbuild/qtbase/src/platformsupport/eventdispatchers/qeventdispatcher_glib.cpp:115
No locals.
#32 0xb55fb493 in QEventLoop::processEvents (this=0xbffff038, flags=...)
    at /srcbuild/qtbase/src/corelib/kernel/qeventloop.cpp:128
        d = 0x818a838
#33 0xb55fb7a6 in QEventLoop::exec (this=0xbffff038, flags=...)
    at /srcbuild/qtbase/src/corelib/kernel/qeventloop.cpp:204
        locker = {val = 135270984}
        __PRETTY_FUNCTION__ = "int QEventLoop::exec(QEventLoop::ProcessEventsFlags)"
        ref = {d = 0x818a838, locker = @0xbfffefd4, exceptionCaught = true}
        app = 0xbffff0f8
        d = 0x818a838
#34 0xb55ff2ff in QCoreApplication::exec ()
    at /srcbuild/qtbase/src/corelib/kernel/qcoreapplication.cpp:1216
        threadData = 0x81011c0
        __PRETTY_FUNCTION__ = "static int QCoreApplication::exec()"
        eventLoop = {<QObject> = {
            _vptr.QObject = 0xb595b0a8 <vtable for QEventLoop+8>, 
            static staticMetaObject = {d = {superdata = 0x0, 
                stringdata = 0xb57e0880 <qt_meta_stringdata_QObject>, 
                data = 0xb57e0980 <qt_meta_data_QObject>, 
                static_metacall = 0xb563f194 <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, 
                extradata = 0x0}}, d_ptr = {d = 0x818a838}, 
            static staticQtMetaObject = {d = {superdata = 0x0, 
                stringdata = 0xb582ed80 <qt_meta_stringdata_Qt>, 
                data = 0xb5837480 <qt_meta_data_Qt>, static_metacall = 0x0, 
                relatedMetaObjects = 0x0, extradata = 0x0}}}, 
          static staticMetaObject = {d = {
              superdata = 0xb59554b8 <QObject::staticMetaObject>, 
              stringdata = 0xb5843540 <qt_meta_stringdata_QEventLoop>, 
              data = 0xb58435c0 <qt_meta_data_QEventLoop>, 
              static_metacall = 0xb56d642c <QEventLoop::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, 
              extradata = 0x0}}}
        returnCode = -1241419788
#35 0xb5a2d6be in QGuiApplication::exec ()
    at /srcbuild/qtbase/src/gui/kernel/qguiapplication.cpp:1528
No locals.
#36 0xb6119071 in QApplication::exec ()
    at /srcbuild/qtbase/src/widgets/kernel/qapplication.cpp:2973
No locals.
#37 0x0806e5a0 in main ()
No symbol table info available