Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[New Thread 0x7fffeb58c700 (LWP 750)]
libpng warning: iCCP: Not recognizing known sRGB profile that has been edited
[New Thread 0x7fffca3d5700 (LWP 751)]
[New Thread 0x7fffc9bd4700 (LWP 755)]
[New Thread 0x7fffc93d3700 (LWP 756)]

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) backtrace
#0  0x0000000000000000 in ?? ()
#1  0x00007ffff75b903a in ?? () from /usr/lib/libQt5Widgets.so.5
#2  0x00007fffcbd16902 in QmlEditorWidgets::CustomColorDialog::CustomColorDialog(QWidget*) ()
   from /usr/lib/qtcreator/plugins/QtProject/../../libQmlEditorWidgets.so.1
#3  0x00007fffcbd0c570 in QmlEditorWidgets::ContextPaneWidget::colorDialog() ()
   from /usr/lib/qtcreator/plugins/QtProject/../../libQmlEditorWidgets.so.1
#4  0x00007fffcbd0db30 in QmlEditorWidgets::ContextPaneWidget::ContextPaneWidget(QWidget*) ()
   from /usr/lib/qtcreator/plugins/QtProject/../../libQmlEditorWidgets.so.1
#5  0x00007fffcbfb253f in ?? ()
   from /usr/lib/qtcreator/plugins/QtProject/libQmlJSEditor.so
#6  0x00007fffcbfb372e in ?? ()
   from /usr/lib/qtcreator/plugins/QtProject/libQmlJSEditor.so
#7  0x00007fffcbf9594e in ?? ()
   from /usr/lib/qtcreator/plugins/QtProject/libQmlJSEditor.so
#8  0x00007ffff7bc16a6 in ExtensionSystem::Internal::PluginSpecPrivate::initializePlugin() () from /usr/bin/../lib/qtcreator/libExtensionSystem.so.1
#9  0x00007ffff7bbbbbc in ExtensionSystem::Internal::PluginManagerPrivate::loadPlugin(ExtensionSystem::PluginSpec*, ExtensionSystem::PluginSpec::State) ()
   from /usr/bin/../lib/qtcreator/libExtensionSystem.so.1
#10 0x00007ffff7bbc0d7 in ExtensionSystem::Internal::PluginManagerPrivate::loadPlugins() () from /usr/bin/../lib/qtcreator/libExtensionSystem.so.1
#11 0x0000000000409e30 in ?? ()
#12 0x00007ffff5730000 in __libc_start_main () from /usr/lib/libc.so.6
#13 0x000000000040a214 in ?? ()
(gdb)