Qt's tlwRect.size() reports 16 GByte
While trying to run the app Stellarium
on the L5, this fails with a message
qt.qpa.xcb: xcb_shm_create_segment() can't be called for size 17179344900
The maintainer of stellarium reports that this comes out of Qt from tlwRect.size()
in qwidgetrepaintmanager.cpp
reporting this size of "top-level window". See also the thread https://github.com/Stellarium/stellarium/discussions/2831#