/usr/share/lua/5.3/posix/sys.lua is in lua-posix 33.4.0-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/lua/5.3/posix/../../5.1/posix/sys.lua
/usr/share/lua/5.3/posix/../../5.1/posix/sys.lua