/usr/share/doc/libgnomecanvasmm-2.6-dev/README is in libgnomecanvasmm-2.6-dev 2.26.0-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgnomecanvasmm-2.6-dev/../libgnomecanvasmm-2.6-1v5/README