/usr/lib/x86_64-linux-gnu/libwnckmm-1.0.so is in libwnckmm-1.0-0-dev 0.1.1-2+b2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libwnckmm-1.0.so.0.1.0
/usr/lib/x86_64-linux-gnu/libwnckmm-1.0.so.0.1.0