(gdb) start
Temporary breakpoint 2 at 0x403510: file /usr/src/debug/freecad-0.19.2/src/Main/MainGui.cpp, line 118.
Starting program: /usr/bin/freecad 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/libthread_db.so.1".

Temporary breakpoint 2, main (argc=1, argv=0xbffff884) at /usr/src/debug/freecad-0.19.2/src/Main/MainGui.cpp:118
118     {
(gdb) cont
Continuing.
FreeCAD 0.19, Libs: 0.19RUnknown
© Juergen Riegel, Werner Mayer, Yorik van Havre and others 2001-2021
FreeCAD is free and open-source software licensed under the terms of LGPL2+ license.
FreeCAD wouldn't be possible without FreeCAD community.
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[New Thread 0xafb58b00 (LWP 22204)]
[New Thread 0xa84bab00 (LWP 22205)]
[New Thread 0xa77e9b00 (LWP 22206)]
[New Thread 0x9b894b00 (LWP 22207)]

Thread 1 "freecad" received signal SIGSEGV, Segmentation fault.
0xb5b9dbe8 in QBackingStore::beginPaint (this=0xaf2066d0, region=...) at painting/qbackingstore.cpp:147
147         if (QHighDpiScaling::isActive() && device->devType() == QInternal::Image) {
(gdb) print device
$1 = (QPaintDevice *) 0x0