/usr/lib/x86_64-linux-gnu/libtrilinos_ml.so is in libtrilinos-ml-dev 12.4.2-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libtrilinos_ml.so.12
/usr/lib/x86_64-linux-gnu/libtrilinos_ml.so.12