Thread 2 (Thread 0x7fffee00c700 (LWP 21570)):
#0  0x00007ffff67dc03d in recvmsg () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007ffff16b19b7 in _xcb_in_read (c=c@entry=0x615ab0) at ../../src/xcb_in.c:903
        n = <optimized out>
        iov = {iov_base = 0x615b24, iov_len = 4096}
        cmsgbuf = {cmsghdr = {cmsg_len = 140737186413712, cmsg_level = 1, cmsg_type = 0, __cmsg_data = 0x7fffee00bc70 "\220\274"}, buf = "\220\274\000\356\377\177\000\000\001\000\000\000\000\000\000\000\220\274\000\356\377\177\000\000T\305\004\367\377\177\000\000\260\274\000\356\377\177\000\000 \275\000\356\377\177\000\000\260\274\000\356\377\177\000\000\016\305\004\367\377\177\000\000\005\000\000\000\000\000\000\000 \275\000\356\377\177\000"}
        msg = {msg_name = 0x0, msg_namelen = 0, msg_iov = 0x7fffee00bc10, msg_iovlen = 1, msg_control = 0x7fffee00bc60, msg_controllen = 0, msg_flags = 0}
#2  0x00007ffff16afdd7 in _xcb_conn_wait (c=c@entry=0x615ab0, cond=cond@entry=0x615af0, vector=vector@entry=0x0, count=count@entry=0x0) at ../../src/xcb_conn.c:483
        may_read = 1
        ret = 1
        fd = {fd = 3, events = 1, revents = 1}
#3  0x00007ffff16b164f in xcb_wait_for_event (c=0x615ab0) at ../../src/xcb_in.c:622
        ret = 0x0
#4  0x00007ffff7ec3ac7 in QXcbEventReader::run (this=0x623ee0) at qxcbconnection.cpp:1099
        event = 0x0
#5  0x00007ffff70762c1 in QThreadPrivate::start (arg=0x623ee0) at thread/qthread_unix.cpp:337
        __clframe = {__cancel_routine = 0x7ffff7076348 <QThreadPrivate::finish(void*)>, __cancel_arg = 0x623ee0, __do_it = 1, __cancel_type = 32767}
        thr = 0x623ee0
        data = 0x624240
        objectName = {static null = {<No data fields>}, d = 0x7ffff73c6bc0 <QArrayData::shared_null>}
#6  0x00007ffff5e13182 in start_thread (arg=0x7fffee00c700) at pthread_create.c:312
        __res = <optimized out>
        pd = 0x7fffee00c700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140737186416384, -6186961818256138882, 1, 0, 140737186417088, 140737186416384, 6186999212424568190, 6186983557457124734}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#7  0x00007ffff67db00d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
No locals.

Thread 1 (Thread 0x7ffff7fc5780 (LWP 21566)):
#0  QWidget::setVisible (this=0x67bb70, visible=false) at kernel/qwidget.cpp:8095
        d = 0x7ffff6044378
        hideToParentEvent = {_vptr.QEvent = 0x8, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74f2860 <qt_meta_stringdata_QEvent>, data = 0x7ffff74f4260 <qt_meta_data_QEvent>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}, d = 0x7ffff7bcc8dd, t = 52144, posted = 1, spont = 1, m_accept = 1, reserved = 8191}
        __PRETTY_FUNCTION__ = "virtual void QWidget::setVisible(bool)"
        __FUNCTION__ = "setVisible"
#1  0x00007ffff77b5b80 in QWidget::hide (this=0x67bb70) at kernel/qwidget.cpp:7882
No locals.
#2  0x00007ffff77b6e75 in QWidgetPrivate::close_helper (this=0x67c070, mode=QWidgetPrivate::CloseWithEvent) at kernel/qwidget.cpp:8252
        q = 0x67bb70
        that = {wp = {d = 0x6429f0, value = 0x67bb70}}
        parentWidget = {wp = {d = 0x65f470, value = 0x654cf0}}
        quitOnClose = false
#3  0x00007ffff77b7043 in QWidget::close (this=0x67bb70) at kernel/qwidget.cpp:8313
No locals.
#4  0x00007ffff77b54d7 in QWidgetPrivate::show_helper (this=0x67cfe0) at kernel/qwidget.cpp:7751
        q = 0x647050
        isEmbedded = false
        showEvent = {<QEvent> = {_vptr.QEvent = 0x7fffffffcd00, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74f2860 <qt_meta_stringdata_QEvent>, data = 0x7ffff74f4260 <qt_meta_data_QEvent>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}, d = 0x647050, t = 1, posted = 0, spont = 0, m_accept = 0, reserved = 0}, <No data fields>}
#5  0x00007ffff77b6565 in QWidget::setVisible (this=0x647050, visible=true) at kernel/qwidget.cpp:8086
        d = 0x67cfe0
        pw = 0x0
        wasResized = true
        initialWindowState = {i = 0}
        needUpdateGeometry = false
        showToParentEvent = {_vptr.QEvent = 0xfffffcda0, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74f2860 <qt_meta_stringdata_QEvent>, data = 0x7ffff74f4260 <qt_meta_data_QEvent>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}, d = 0x647050, t = 52656, posted = 1, spont = 1, m_accept = 1, reserved = 8191}
        __PRETTY_FUNCTION__ = "virtual void QWidget::setVisible(bool)"
        __FUNCTION__ = "setVisible"
#6  0x000000000040372d in MainWindow::timerEvent (this=0x7fffffffd890, evt=0x7fffffffd610) at ../QTBUG-43780/mainwindow.cpp:38
        value = true
#7  0x00007ffff73298aa in QObject::event (this=0x7fffffffd890, e=0x7fffffffd610) at kernel/qobject.cpp:1226
No locals.
#8  0x00007ffff77b8f24 in QWidget::event (this=0x7fffffffd890, event=0x7fffffffd610) at kernel/qwidget.cpp:9085
        d = 0x6591f0
#9  0x00007ffff78fcf8a in QMainWindow::event (this=0x7fffffffd890, event=0x7fffffffd610) at widgets/qmainwindow.cpp:1495
        d = 0x6591f0
#10 0x00007ffff77698cc in QApplicationPrivate::notify_helper (this=0x607a80, receiver=0x7fffffffd890, e=0x7fffffffd610) at kernel/qapplication.cpp:3722
        consumed = false
#11 0x00007ffff776972f in QApplication::notify (this=0x7fffffffd880, receiver=0x7fffffffd890, e=0x7fffffffd610) at kernel/qapplication.cpp:3687
        d = 0x607a80
        __PRETTY_FUNCTION__ = "virtual bool QApplication::notify(QObject*, QEvent*)"
        res = false
#12 0x00007ffff72ecdf2 in QCoreApplication::notifyInternal (this=0x7fffffffd880, receiver=0x7fffffffd890, event=0x7fffffffd610) at kernel/qcoreapplication.cpp:930
        threadData = 0x607bf0
        loopLevelCounter = {threadData = 0x607bf0}
        result = false
        cbdata = {0x7fffffffd890, 0x7fffffffd610, 0x7fffffffd54f}
        d = 0x6591f0
#13 0x00007ffff72f09a5 in QCoreApplication::sendEvent (receiver=0x7fffffffd890, event=0x7fffffffd610) at kernel/qcoreapplication.h:228
No locals.
#14 0x00007ffff7363fb4 in QTimerInfoList::activateTimers (this=0x6529a8) at kernel/qtimerinfo_unix.cpp:635
        e = {<QEvent> = {_vptr.QEvent = 0x7ffff75dfb30 <vtable for QTimerEvent+16>, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74f2860 <qt_meta_stringdata_QEvent>, data = 0x7ffff74f4260 <qt_meta_data_QEvent>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}, d = 0x0, t = 1, posted = 0, spont = 0, m_accept = 1, reserved = 8191}, id = 3}
        currentTimerInfo = 0x686d60
        n_act = 1
        maxCount = 0
        currentTime = {tv_sec = 23438, tv_nsec = 500909417}
#15 0x00007ffff7361ecb in QEventDispatcherUNIX::activateTimers (this=0x6254c0) at kernel/qeventdispatcher_unix.cpp:549
        d = 0x652170
#16 0x00007ffff7362238 in QEventDispatcherUNIX::processEvents (this=0x6254c0, flags=...) at kernel/qeventdispatcher_unix.cpp:611
        tm = 0x7fffffffd6e0
        wait_tm = {tv_sec = 0, tv_nsec = 200000000}
        d = 0x652170
        nevents = 0
        canWait = true
#17 0x00007ffff7f591fe in QUnixEventDispatcherQPA::processEvents (this=0x6254c0, flags=...) at eventdispatchers/qunixeventdispatcher.cpp:62
        didSendEvents = false
#18 0x00007ffff72e9b50 in QEventLoop::processEvents (this=0x7fffffffd810, flags=...) at kernel/qeventloop.cpp:128
        d = 0x77c8b0
#19 0x00007ffff72e9e11 in QEventLoop::exec (this=0x7fffffffd810, flags=...) at kernel/qeventloop.cpp:204
        locker = {val = 6323424}
        __PRETTY_FUNCTION__ = "int QEventLoop::exec(QEventLoop::ProcessEventsFlags)"
        ref = {d = 0x77c8b0, locker = @0x7fffffffd790, exceptionCaught = true}
        app = 0x7fffffffd880
        d = 0x77c8b0
#20 0x00007ffff72ed4ca in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1183
        threadData = 0x607bf0
        __PRETTY_FUNCTION__ = "static int QCoreApplication::exec()"
        eventLoop = {<QObject> = {_vptr.QObject = 0x7ffff75e33b0 <vtable for QEventLoop+16>, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff748e6c0 <qt_meta_stringdata_QObject>, data = 0x7ffff748e7e0 <qt_meta_data_QObject>, static_metacall = 0x7ffff7332a32 <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, d_ptr = {d = 0x77c8b0}, static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74db400 <qt_meta_stringdata_Qt>, data = 0x7ffff74e5780 <qt_meta_data_Qt>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x7ffff75dfc80 <QObject::staticMetaObject>, stringdata = 0x7ffff74f2360 <qt_meta_stringdata_QEventLoop>, data = 0x7ffff74f23c0 <qt_meta_data_QEventLoop>, static_metacall = 0x7ffff73bc79e <QEventLoop::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}}
        returnCode = 0
#21 0x00007ffff6125a64 in QGuiApplication::exec () at kernel/qguiapplication.cpp:1507
No locals.
#22 0x00007ffff7766653 in QApplication::exec () at kernel/qapplication.cpp:2956
No locals.
#23 0x00000000004033f8 in main (argc=1, argv=0x7fffffffd9d8) at ../QTBUG-43780/main.cpp:10
        a = {<QGuiApplication> = {<QCoreApplication> = {<QObject> = {_vptr.QObject = 0x7ffff7da68d0 <vtable for QApplication+16>, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff748e6c0 <qt_meta_stringdata_QObject>, data = 0x7ffff748e7e0 <qt_meta_data_QObject>, static_metacall = 0x7ffff7332a32 <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, d_ptr = {d = 0x607a80}, static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74db400 <qt_meta_stringdata_Qt>, data = 0x7ffff74e5780 <qt_meta_data_Qt>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x7ffff75dfc80 <QObject::staticMetaObject>, stringdata = 0x7ffff74f24e0 <qt_meta_stringdata_QCoreApplication>, data = 0x7ffff74f2700 <qt_meta_data_QCoreApplication>, static_metacall = 0x7ffff73bc8f6 <QCoreApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, static self = 0x7fffffffd880}, static staticMetaObject = {d = {superdata = 0x7ffff75e3440 <QCoreApplication::staticMetaObject>, stringdata = 0x7ffff653e6c0 <qt_meta_stringdata_QGuiApplication>, data = 0x7ffff653eba0 <qt_meta_data_QGuiApplication>, static_metacall = 0x7ffff612c0e0 <QGuiApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x7ffff66c93c0 <QGuiApplication::staticMetaObject>, stringdata = 0x7ffff7bc71a0 <qt_meta_stringdata_QApplication>, data = 0x7ffff7bc74c0 <qt_meta_data_QApplication>, static_metacall = 0x7ffff776b8a0 <QApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}}
        w = {<QMainWindow> = {<QWidget> = {<QObject> = {_vptr.QObject = 0x605bb0 <vtable for MainWindow+16>, static staticMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff748e6c0 <qt_meta_stringdata_QObject>, data = 0x7ffff748e7e0 <qt_meta_data_QObject>, static_metacall = 0x7ffff7332a32 <QObject::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, d_ptr = {d = 0x6591f0}, static staticQtMetaObject = {d = {superdata = 0x0, stringdata = 0x7ffff74db400 <qt_meta_stringdata_Qt>, data = 0x7ffff74e5780 <qt_meta_data_Qt>, static_metacall = 0x0, relatedMetaObjects = 0x0, extradata = 0x0}}}, <QPaintDevice> = {_vptr.QPaintDevice = 0x605d68 <vtable for MainWindow+456>, painters = 0, reserved = 0x0}, static staticMetaObject = {d = {superdata = 0x7ffff75dfc80 <QObject::staticMetaObject>, stringdata = 0x7ffff7bcd960 <qt_meta_stringdata_QWidget>, data = 0x7ffff7bce6e0 <qt_meta_data_QWidget>, static_metacall = 0x7ffff77c0360 <QWidget::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, data = 0x659320}, static staticMetaObject = {d = {superdata = 0x7ffff7da7560 <QWidget::staticMetaObject>, stringdata = 0x7ffff7c90780 <qt_meta_stringdata_QMainWindow>, data = 0x7ffff7c90b80 <qt_meta_data_QMainWindow>, static_metacall = 0x7ffff7bb6224 <QMainWindow::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x7ffff7dcb390 <qt_meta_extradata_QMainWindow>, extradata = 0x0}}}, static staticMetaObject = {d = {superdata = 0x7ffff7dcb360 <QMainWindow::staticMetaObject>, stringdata = 0x404960 <qt_meta_stringdata_MainWindow>, data = 0x4049a0 <qt_meta_data_MainWindow>, static_metacall = 0x404618 <MainWindow::qt_static_metacall(QObject*, QMetaObject::Call, int, void**)>, relatedMetaObjects = 0x0, extradata = 0x0}}, ui = 0x65e130, mScrollBar = 0x647050, proxyWidget = 0x404750 <__libc_csu_init>}