/usr/share/doc/libgstreamer-plugins-base0.10-dev/README.gz is in libgstreamer-plugins-base0.10-dev 0.10.36-1.1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgstreamer-plugins-base0.10-dev/../libgstreamer-plugins-base0.10-0/README.gz