Description of problem:

LuaRocks from EPEL6 installs shared libraries into wrong directory (/usr/lib instead of /usr/lib64).

Version-Release number of selected component (if applicable):

luarocks 2.1.2-1.el6

How reproducible:

Install luarocks from EPEL6 and then try to install some binary rock using luarocks install.

Steps to Reproduce:
1. docker run -t -i centos:6
2. yum install -y http://mirror.logol.ru/epel/6/x86_64/epel-release-6-8.noarch.rpm
3. yum install luarocks
4. yum install gcc unzip - see https://bugzilla.redhat.com/show_bug.cgi?id=1367681
5. luarocks install luafilesystem
6. lua
> require('lfs')

Actual results:

# luarocks install luafilesystem
Installing http://www.luarocks.org/repositories/rocks/luafilesystem-1.6.3-2.src.rock...
Using http://www.luarocks.org/repositories/rocks/luafilesystem-1.6.3-2.src.rock... switching to 'build' mode
gcc -O2 -fPIC -I/usr/include -c src/lfs.c -o src/lfs.o
gcc -shared -o lfs.so -L/usr/lib src/lfs.o
Updating manifest for /usr/lib/luarocks/rocks


# lua
Lua 5.1.4  Copyright (C) 1994-2008 Lua.org, PUC-Rio
> =package.path
./?.lua;/usr/share/lua/5.1/?.lua;/usr/share/lua/5.1/?/init.lua;/usr/lib64/lua/5.1/?.lua;/usr/lib64/lua/5.1/?/init.lua
> require('lfs')
stdin:1: module 'lfs' not found:
	no field package.preload['lfs']
	no file './lfs.lua'
	no file '/usr/share/lua/5.1/lfs.lua'
	no file '/usr/share/lua/5.1/lfs/init.lua'
	no file '/usr/lib64/lua/5.1/lfs.lua'
	no file '/usr/lib64/lua/5.1/lfs/init.lua'
	no file './lfs.so'
	no file '/usr/lib64/lua/5.1/lfs.so'
	no file '/usr/lib64/lua/5.1/loadall.so'
stack traceback:
	[C]: in function 'require'
	stdin:1: in main chunk
	[C]: ?
> 

ls -l /usr/lib/lua/5.1/lfs.so 

Expected results:

On x86_64 shared libraries must be installed to /usr/lib64 instead of /usr/lib

ls -l /usr/lib64/lua/5.1/lfs.so 

Additional info:

cat /etc/luarocks/config-5.1.lua:
rocks_trees = {
   { name = [[user]], root = home..[[/.luarocks]] },
   { name = [[system]], root = [[/usr]], lib_dir = [[/usr/lib64/lua/5.1]] }
}

fix is to add lib_dir = [[/usr/lib64/lua/5.1]] on x86_64:
rocks_trees = {
   { name = [[user]], root = home..[[/.luarocks]] },
   { name = [[system]], root = [[/usr]], lib_dir = [[/usr/lib64/lua/5.1]] }
}