This file is indexed.

/lib/modules/3.16.0-31-lowlatency/build is in linux-headers-3.16.0-31-lowlatency 3.16.0-31.43~14.04.1.

This file is owned by root:root, with mode 0o777.

It is a symlink to /usr/src/linux-headers-3.16.0-31-lowlatency