luajit vs luajit2

[IlyaIndigo]

Hello! I'm a nginx maintainer in openSUSE and I recently had a need to build nginx-lua-module for redis access and I just now found out about luajit and luajit2 and I want to figure out whether I should replace luajit with luajit2, make them alternatives or use luajit2 only for nginx-module-lua.

What is the difference in them and what are the advantages and disadvantages of each over the other. OpenResty claims luagit2 works much better with mginx-module-lua. That's all I understand so far. Why can't OpenResty patches just be added to upstream? Is it possible to replace luajit with luajit2 in the operating system and what consequences will this cause, for example for gegl used in gimp? Or does luajit2 work better only with nginx-module-lua and luajit is better for everything else? https://github.com/LuaJIT/LuaJIT/issues/1191