Lua modules available at LuaRocks can be installed locally to the project:
luarocks install --lua-version 5.1 --tree <local modules folder name> <module name>TIP: put an empty .gdignore file in the local modules folder, so that
Godot doesn't try importing the installed *.lua files as Lua scripts.
Adjust the package paths using the Lua PluginScript project settings
and scripts should be able to require the installed modules.
For example, if the local modules folder is called localrocks, add
res://localrocks/share/lua/5.1/?.lua and res://localrocks/share/lua/5.1/?/init.lua
to Package Path and res://localrocks/lib/lua/5.1/?.so (change extension
to .dll on Windows and possibly .dylib on OSX) to Package C Path.