Is there a typo in the version number? As per the official luatex [website](http://luatex.org/roadmap.html), _"version 1.08 was __released shortly after TeXLive 2018__ and has some low level changes, most noticeably reworked direction nodes. The interfaces are downward compatible. This version also default to Lua 5.3 which gives a small performance boost._"
Best Regards, Krishna
