/usr/lib/x86_64-linux-gnu/pkgconfig/python3-dbg.pc is in python3-dbg 3.5.1-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/pkgconfig/python-3.5-dbg.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/python-3.5-dbg.pc