Embed extra search paths into Lua build?

[Christopher Tallman <cjtallman@...>]

Is there an easy way to build Lua with additional package search
paths? I searched and didn't see any compile-time way to add in extra
paths to the defaults apart from explicitly editing luaconf.h.

Ideally, I would be able to add in a preprocessor definition like
-DLUA_PATH_EXTRA="./modules/?.lua" when compiling and wouldn't have to
change the actual source (so we can keep the same build process for
subsequent versions).

Is something like this already provided? Am I stuck with changing
LUA_PATH_DEFAULT and LUA_CPATH_DEFAULT in luaconf.h?

Thank you