/usr/lib/x86_64-linux-gnu/libclthreads.so.2 is in libclthreads2 2.4.0-7ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libclthreads.so.2.4.0
/usr/lib/x86_64-linux-gnu/libclthreads.so.2.4.0