* Support a `system' argument for if you want to do hacky things like

change a NixOS installation from x86_64-linux to i686-linux (or vice
  versa if you have distributed builds enabled - I used this upgrade
  from 32-bit to 64-bit NixOS).

svn path=/nixos/trunk/; revision=18177

default.nix

@@ -1,13 +1,18 @@
 { configuration ? import ./lib/from-env.nix "NIXOS_CONFIG" /etc/nixos/configuration.nix
+, system ? builtins.currentSystem
 }:
 
 let
   
-  eval = import ./lib/eval-config.nix { modules = [ configuration ]; };
+  eval = import ./lib/eval-config.nix {
+    inherit system;
+    modules = [ configuration ];
+  };
 
   inherit (eval) config pkgs;
 
   vmConfig = (import ./lib/eval-config.nix {
+    inherit system;
     modules = [ configuration ./modules/virtualisation/qemu-vm.nix ];
   }).config;