This Lumen predates that Lumen by a few years.

We did a search when we picked the name, and found https://github.com/xopxe/Lumen. I emailed Jorge to ask if he was ok with us using the name for a Lisp-to-Lua project and he sent a delightful reply that began "It's impossible to avoid conflicts with such a cool name", and pointed out that there were other projects called lumen that he discovered when he published on Github. Who knows how far back the lumens go.