Arch Linux

Description:
usr/share/lua/5.2/luarocks/site_config.lua has the system architecture hardcoded to x86_64 with line 10:
LUAROCKS_UNAME_M=[[x86_64]]
This incorrectly allows for 64-bit binary rocks to be installed on a 32-bit system (see https://github.com/keplerproject/luarocks/issues/258). The package's architecture is specified to be "any".

Steps to reproduce:
Install a 64-bit binary rock on a 32-bit system with luarocks.

Solution:
A simple solution would be to omit the LUAROCKS_UNAME_M definition in site_config.lua. This will force a dynamic lookup of the architecture in install.lua for each binary rock install, which imposes some time penalty, but would easily allow the package to stay consistent with its "any" architecture type. Another solution would be to populate the LUAROCKS_UNAME_M field of site_config.lua in a post-install step with the contents of `uname -m`. This would require a post-install script of some sort.