/usr/share/doc/gfortran-5-alpha-linux-gnu is in gfortran-5-alpha-linux-gnu 5.3.1-14ubuntu2cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-5-alpha-linux-gnu-base
/usr/share/doc/gcc-5-alpha-linux-gnu-base