Qt executables are miscompiled with LTO

Thread 1 "designer6" received signal SIGSEGV, Segmentation fault.
doActivate<false> (sender=0x0, signal_index=9, argv=0x7fffffffd6c0)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/corelib/kernel/qobject.cpp:3861
3861        QObjectPrivate *sp = QObjectPrivate::get(sender);                                                                                             
(gdb) bt
#0  doActivate<false> (sender=0x0, signal_index=9, argv=0x7fffffffd6c0)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/corelib/kernel/qobject.cpp:3861
#1  0x00007ffff659db87 in QGuiApplication::screenAdded (this=<optimized out>, _t1=<optimized out>)
    at /usr/src/debug/qt6-base/build/src/gui/Gui_autogen/include/moc_qguiapplication.cpp:485
#2  0x00007ffff65fc0d3 in QWindowSystemInterface::handleScreenAdded (ps=<optimized out>, isPrimary=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/gui/kernel/qwindowsysteminterface.cpp:762
#3  0x00007ffff27ead66 in QXcbConnection::initializeScreens (this=0x555555618f60, initialized=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/plugins/platforms/xcb/qxcbconnection_screens.cpp:347
#4  0x00007ffff27dc1d2 in QXcbConnection::QXcbConnection (this=<optimized out>, nativeInterface=<optimized out>, canGrabServer=<optimized out>, 
    defaultVisualId=<optimized out>, displayName=<optimized out>, this=<optimized out>, nativeInterface=<optimized out>, canGrabServer=<optimized out>, 
    defaultVisualId=<optimized out>, displayName=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/plugins/platforms/xcb/qxcbconnection.cpp:72
#5  0x00007ffff2806008 in QXcbIntegration::QXcbIntegration (this=<optimized out>, parameters=..., argc=<optimized out>, argv=<optimized out>, 
    this=<optimized out>, parameters=..., argc=<optimized out>, argv=<optimized out>)
    at /usr/src/debug/qt6-base/build/include/QtCore/../../../qtbase-everywhere-src-6.4.3/src/corelib/tools/qscopedpointer.h:104
#6  0x00007ffff4e8b353 in QXcbIntegrationPlugin::create (this=<optimized out>, system=..., parameters=..., argc=@0x7fffffffe02c: 1, argv=0x7fffffffe388)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/plugins/platforms/xcb/qxcbmain.cpp:22
#7  0x00007ffff6596353 in init_platform (argv=<optimized out>, argc=@0x7fffffffe02c: 1, platformThemeName=..., platformPluginPath=..., 
    pluginNamesWithArguments=...) at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/gui/kernel/qguiapplication.cpp:1192
#8  QGuiApplicationPrivate::createPlatformIntegration (this=0x555555604870)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/gui/kernel/qguiapplication.cpp:1472
#9  0x00007ffff6597a09 in QGuiApplicationPrivate::createEventDispatcher (this=<optimized out>)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/gui/kernel/qguiapplication.cpp:1489
#10 0x00007ffff5f2fb4c in QCoreApplicationPrivate::init (this=this@entry=0x555555604870)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/corelib/kernel/qcoreapplication.cpp:814
#11 0x00007ffff6597a91 in QGuiApplicationPrivate::init (this=this@entry=0x555555604870)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/gui/kernel/qguiapplication.cpp:1513
#12 0x00007ffff6d6c92e in QApplicationPrivate::init (this=0x555555604870)
    at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/widgets/kernel/qapplication.cpp:462
#13 0x00007ffff6d6ca52 in QApplication::QApplication (this=<optimized out>, argc=<optimized out>, argv=<optimized out>, this=<optimized out>, 
    argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/qt6-base/qtbase-everywhere-src-6.4.3/src/widgets/kernel/qapplication.cpp:450
#14 0x000055555557566a in QDesigner::QDesigner (argv=<optimized out>, argc=@0x7fffffffe02c: 1, this=0x7fffffffe1b0)
    at /usr/src/debug/qt6-tools/qttools-everywhere-src-6.4.3/src/designer/src/designer/qdesigner.cpp:56
#15 main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/qt6-tools/qttools-everywhere-src-6.4.3/src/designer/src/designer/main.cpp:28