Further to this, you will need the git head of LuaRocks from https://github.com/keplerproject/luarocks, or release 2.0.10 (the current 2.0.11's make install is broken); 2.0.9, as shipped in Ubuntu quantal, may work (it has the necessary Lua 5.2 support), but anything older definitely won't, and there's quite possibly a patch somewhere since then that I rely on in one of the various packages above.