[gucci-on-fleek]

The dependencies might have a minimum C++ version, but I'd be pretty surprised if the core LuaTeX files couldn't be compiled with C99/C11. The recent C23 commits are just about adding support for compiling in C23 mode, so the main change is no longer using the implicit "everything is an int" function prototypes.

[Rochus]

Thanks. The HB C++17 dependency is already a show-stopper for me. I want to be able to build everything on GCC 4.8, or even better 4.7. I also did some research what actually changed since 1.18.0 and didn't find features my project would depend on.