/usr/share/lua/5.2/luassert/mock.lua is in lua-luassert 1.7.10-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/lua/5.2/luassert/../../5.1/luassert/mock.lua
/usr/share/lua/5.2/luassert/../../5.1/luassert/mock.lua