/usr/lib/x86_64-linux-gnu/libcojets.so is in libcojets2-dev 20061220+dfsg3-3.1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcojets.so.2_gfortran.2006
/usr/lib/x86_64-linux-gnu/libcojets.so.2_gfortran.2006