/usr/lib/x86_64-linux-gnu/libdunepdelab.so is in libdune-pdelab-dev 2.5.0~rc1-2build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libdunepdelab.so.2.5-dev
/usr/lib/x86_64-linux-gnu/libdunepdelab.so.2.5-dev