/usr/share/man/man1/x86_64-linux-gnu-python3.5-dbg-config.1.gz is in libpython3.5-dbg 3.5.3-1+deb9u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/x86_64-linux-gnu-python3.5m-config.1.gz