[luatex] using lualibs

[Herbert Voss]

I thought that I could use the lualibs modules when running
a lua file with texlua:

texlua test.lua

throws an error:

... module 'lualibs-unicode' not found:
        no field package.preload['lualibs-unicode']



--  test.lua
require ("lualibs-unicode")
print("Hello")

up-to-date TL2018 with LuaTeX, Version 1.09.0

Herbert