/usr/lib/x86_64-linux-gnu/libdunegeometry.so is in libdune-geometry-dev 2.3.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libdunegeometry-2.3.1.so
/usr/lib/x86_64-linux-gnu/libdunegeometry-2.3.1.so