/usr/lib/x86_64-linux-gnu/qtchooser/4.conf is in qtchooser 63-g13a3d08-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/qtchooser/../../../share/qtchooser/qt4-x86_64-linux-gnu.conf