(gdb) thread apply all bt

Thread 7 (Thread 0x7fffb6525700 (LWP 23384)):
#0  0x00007ffff1b2c8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fffee6f21ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffee6f22fc in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff275e29b in QEventDispatcherGlib::processEvents (this=0x7fffa40008c0,
    flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007ffff270475a in QEventLoop::exec (this=this@entry=0x7fffb6524dc0,
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007ffff25223d4 in QThread::exec (this=<optimised out>)
    at thread/qthread.cpp:503
#6  0x00007ffff25272be in QThreadPrivate::start (arg=0x5ae3200)
    at thread/qthread_unix.cpp:337
#7  0x00007ffff0a506aa in start_thread (arg=0x7fffb6525700) at pthread_create.c:333
#8  0x00007ffff1b37eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7fffb6d26700 (LWP 23383)):
#0  0x00007ffff1b2c8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fffee6f21ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffee6f22fc in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff275e29b in QEventDispatcherGlib::processEvents (this=0x7fffac0008c0,
    flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007ffff270475a in QEventLoop::exec (this=this@entry=0x7fffb6d25dc0,
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007ffff25223d4 in QThread::exec (this=<optimised out>)
    at thread/qthread.cpp:503
#6  0x00007ffff25272be in QThreadPrivate::start (arg=0x42fe3c0)
    at thread/qthread_unix.cpp:337
#7  0x00007ffff0a506aa in start_thread (arg=0x7fffb6d26700) at pthread_create.c:333
#8  0x00007ffff1b37eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7fffbd572700 (LWP 23381)):
#0  0x00007ffff1b2c8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fffee6f21ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffee6f22fc in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#3  0x00007ffff275e27f in QEventDispatcherGlib::processEvents (this=0x7fffb00008c0,
    flags=...) at kernel/qeventdispatcher_glib.cpp:418
#4  0x00007ffff270475a in QEventLoop::exec (this=this@entry=0x7fffbd571da0,
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007ffff25223d4 in QThread::exec (this=<optimised out>)
    at thread/qthread.cpp:503
#6  0x00007ffff06e2f85 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007ffff25272be in QThreadPrivate::start (arg=0x24556a0)
    at thread/qthread_unix.cpp:337
#8  0x00007ffff0a506aa in start_thread (arg=0x7fffbd572700) at pthread_create.c:333
#9  0x00007ffff1b37eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fffbe573700 (LWP 23380)):
#0  0x00007ffff1b2c8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fffee6f21ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffee6f22fc in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff275e27f in QEventDispatcherGlib::processEvents (this=0x7fffb80008c0,
    flags=...) at kernel/qeventdispatcher_glib.cpp:418
#4  0x00007ffff270475a in QEventLoop::exec (this=this@entry=0x7fffbe572da0,
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007ffff25223d4 in QThread::exec (this=<optimised out>)
    at thread/qthread.cpp:503
#6  0x00007ffff06e2f85 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007ffff25272be in QThreadPrivate::start (arg=0x18912c0)
    at thread/qthread_unix.cpp:337
#8  0x00007ffff0a506aa in start_thread (arg=0x7fffbe573700) at pthread_create.c:333
#9  0x00007ffff1b37eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fffc4704700 (LWP 23379)):
#0  0x00007ffff1b2c8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fffc99c312c in ?? () from /lib/x86_64-linux-gnu/libusb-1.0.so.0
#2  0x00007ffff0a506aa in start_thread (arg=0x7fffc4704700) at pthread_create.c:333
#3  0x00007ffff1b37eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fffe3979700 (LWP 23378)):
#0  0x00007ffff1b2c8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fffeca72bd2 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
---Type <return> to continue, or q <return> to quit---
#2  0x00007fffeca7474f in xcb_wait_for_event ()
   from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fffe5ec7a39 in QXcbEventReader::run (this=0xbb29a0)
    at qxcbconnection.cpp:1105
#4  0x00007ffff25272be in QThreadPrivate::start (arg=0xbb29a0)
    at thread/qthread_unix.cpp:337
#5  0x00007ffff0a506aa in start_thread (arg=0x7fffe3979700) at pthread_create.c:333
#6  0x00007ffff1b37eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fffe6390800 (LWP 23374)):
#0  Bin::slotLoadFolders (this=this@entry=0xdecd00, foldersData=...)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/bin/bin.cpp:1035
#1  0x00000000008809c5 in Bin::qt_static_metacall (_o=_o@entry=0xdecd00,
    _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=56,
    _a=_a@entry=0x7fffffffc7f0)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/obj-x86_64-linux-gnu/src/moc_bin.cpp:1011
#2  0x00007ffff273778a in QMetaObject::activate (sender=sender@entry=0x100ec10,
    signalOffset=<optimised out>, local_signal_index=local_signal_index@entry=0,
    argv=argv@entry=0x7fffffffc7f0) at kernel/qobject.cpp:3717
#3  0x00007ffff2737f87 in QMetaObject::activate (sender=sender@entry=0x100ec10,
    m=m@entry=0xb6e980 <BinController::staticMetaObject>,
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7fffffffc7f0)
    at kernel/qobject.cpp:3582
#4  0x000000000086bc62 in BinController::loadFolders (this=this@entry=0x100ec10,
    _t1=...)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/obj-x86_64-linux-gnu/src/moc_bincontroller.cpp:235
#5  0x00000000007d7200 in BinController::initializeBin (this=0x100ec10,
    playlist=<incomplete type>)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/mltcontroller/bincontroller.cpp:87

#6  0x0000000000856e85 in Render::setSceneList (this=0x255d810, playlist=...,
    position=position@entry=1453)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/renderer.cpp:1280
#7  0x000000000055389d in KdenliveDoc::setSceneList (this=0x73c3bd0)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/doc/kdenlivedoc.cpp:305
#8  0x000000000061b94f in Timeline::Timeline (this=0x7c96c20, doc=0x73c3bd0,
---Type <return> to continue, or q <return> to quit---
    actions=..., ok=0x7fffffffccaf, parent=0xc0cd10)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/timeline/timeline.cpp:65
#9  0x00000000005a5bab in ProjectManager::doOpenFile (this=this@entry=0xcb0a90,
    url=..., stale=<optimised out>, stale@entry=0x0)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/project/projectmanager.cpp:484
#10 0x00000000005a777b in ProjectManager::openFile (this=this@entry=0xcb0a90,
    url=...)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/project/projectmanager.cpp:438
#11 0x00000000005a7ac9 in ProjectManager::openFile (this=0xcb0a90)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/project/projectmanager.cpp:334
#12 0x0000000000873f35 in ProjectManager::qt_static_metacall (_o=_o@entry=0xcb0a90,
    _c=_c@entry=QMetaObject::InvokeMetaMethod, _id=_id@entry=4,
    _a=_a@entry=0x7fffffffd030)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/obj-x86_64-linux-gnu/src/moc_projectmanager.cpp:152
#13 0x00007ffff273778a in QMetaObject::activate (sender=sender@entry=0xdd5640,
    signalOffset=<optimised out>, local_signal_index=local_signal_index@entry=1,
    argv=argv@entry=0x7fffffffd030) at kernel/qobject.cpp:3717
#14 0x00007ffff2737f87 in QMetaObject::activate (sender=sender@entry=0xdd5640,
    m=m@entry=0x7ffff3879c80 <QAction::staticMetaObject>,
    local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fffffffd030)
    at kernel/qobject.cpp:3582
#15 0x00007ffff3379172 in QAction::triggered (this=this@entry=0xdd5640, _t1=false)
    at .moc/moc_qaction.cpp:360
#16 0x00007ffff337b618 in QAction::activate (this=0xdd5640, event=<optimised out>)
    at kernel/qaction.cpp:1167
#17 0x00007ffff347be40 in QAbstractButtonPrivate::click (this=0x2ddff10)
    at widgets/qabstractbutton.cpp:516
#18 0x00007ffff347bf74 in QAbstractButton::mouseReleaseEvent (this=0x2ddfcf0, e=
    0x7fffffffd540) at widgets/qabstractbutton.cpp:1132
#19 0x00007ffff353f4ca in QToolButton::mouseReleaseEvent (this=<optimised out>,
    e=<optimised out>) at widgets/qtoolbutton.cpp:609
#20 0x00007ffff33c5188 in QWidget::event (this=0x2ddfcf0,
    event=event@entry=0x7fffffffd540) at kernel/qwidget.cpp:9023
#21 0x00007ffff347ccc3 in QAbstractButton::event (this=this@entry=0x2ddfcf0,
    e=e@entry=0x7fffffffd540) at widgets/qabstractbutton.cpp:1089
#22 0x00007ffff353f5a9 in QToolButton::event (this=0x2ddfcf0, event=0x7fffffffd540)
    at widgets/qtoolbutton.cpp:965
---Type <return> to continue, or q <return> to quit---
#23 0x00007ffff3382b8c in QApplicationPrivate::notify_helper (
    this=this@entry=0xb99eb0, receiver=receiver@entry=0x2ddfcf0,
    e=e@entry=0x7fffffffd540) at kernel/qapplication.cpp:3720
#24 0x00007ffff3388c7a in QApplication::notify (this=<optimised out>,
    receiver=0x2ddfcf0, e=0x7fffffffd540) at kernel/qapplication.cpp:3280
#25 0x00007ffff2706f1b in QCoreApplication::notifyInternal (this=0x7fffffffddf0,
    receiver=receiver@entry=0x2ddfcf0, event=event@entry=0x7fffffffd540)
    at kernel/qcoreapplication.cpp:935
#26 0x00007ffff33876f2 in QCoreApplication::sendSpontaneousEvent (
    event=0x7fffffffd540, receiver=0x2ddfcf0)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#27 QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x2ddfcf0,
    event=event@entry=0x7fffffffd540, alienWidget=alienWidget@entry=0x2ddfcf0,
    nativeWidget=0x2ddabc0,
    buttonDown=buttonDown@entry=0x7ffff38a8a10 <qt_button_down>,
    lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:2751
#28 0x00007ffff33dc440 in QWidgetWindow::handleMouseEvent (
    this=this@entry=0x2dcfc60, event=event@entry=0x7fffffffd960)
    at kernel/qwidgetwindow.cpp:543
#29 0x00007ffff33de78b in QWidgetWindow::event (this=0x2dcfc60, event=0x7fffffffd960)
    at kernel/qwidgetwindow.cpp:210
#30 0x00007ffff3382b8c in QApplicationPrivate::notify_helper (
    this=this@entry=0xb99eb0, receiver=receiver@entry=0x2dcfc60,
    e=e@entry=0x7fffffffd960) at kernel/qapplication.cpp:3720
#31 0x00007ffff3388230 in QApplication::notify (this=0x7fffffffddf0,
    receiver=0x2dcfc60, e=0x7fffffffd960) at kernel/qapplication.cpp:3503
#32 0x00007ffff2706f1b in QCoreApplication::notifyInternal (this=0x7fffffffddf0,
    receiver=receiver@entry=0x2dcfc60, event=event@entry=0x7fffffffd960)
    at kernel/qcoreapplication.cpp:935
#33 0x00007ffff2a293c8 in QCoreApplication::sendSpontaneousEvent (
    event=0x7fffffffd960, receiver=0x2dcfc60)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#34 QGuiApplicationPrivate::processMouseEvent (e=0x6f748a0)
    at kernel/qguiapplication.cpp:1772
#35 0x00007ffff2a2b005 in QGuiApplicationPrivate::processWindowSystemEvent (
    e=e@entry=0x6f748a0) at kernel/qguiapplication.cpp:1576
#36 0x00007ffff2a105b8 in QWindowSystemInterface::sendWindowSystemEvents (flags=...)
    at kernel/qwindowsysteminterface.cpp:572
---Type <return> to continue, or q <return> to quit---
#37 0x00007fffe5ef4250 in userEventSourceDispatch (source=<optimised out>)
    at eventdispatchers/qeventdispatcher_glib.cpp:70
#38 0x00007fffee6f1ff7 in g_main_context_dispatch ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#39 0x00007fffee6f2250 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#40 0x00007fffee6f22fc in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#41 0x00007ffff275e27f in QEventDispatcherGlib::processEvents (this=0xbd7ef0,
    flags=...) at kernel/qeventdispatcher_glib.cpp:418
#42 0x00007ffff270475a in QEventLoop::exec (this=this@entry=0x7fffffffdce0,
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#43 0x00007ffff270c2cc in QCoreApplication::exec ()
    at kernel/qcoreapplication.cpp:1188
#44 0x00007ffff2a2100c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#45 0x00007ffff337f025 in QApplication::exec () at kernel/qapplication.cpp:2956
#46 0x0000000000521e22 in main (argc=1, argv=<optimised out>)
    at /build/kdenlive-Gdwr6P/kdenlive-15.12.0+65/src/main.cpp:118