/usr/share/doc/gimp-dbg/README is in gimp-dbg 2.8.10-0ubuntu1.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gimp-dbg/../libgimp2.0/README
/usr/share/doc/gimp-dbg/../libgimp2.0/README