buildClan: set clanCore.directory and hostPlatform

lib/build-clan/default.nix

@@ -1,4 +1,4 @@
-{ nixpkgs, clan, lib }:
+{ nixpkgs, self, lib }:
 { directory  # The directory containing the machines subdirectory
 , specialArgs ? { } # Extra arguments to pass to nixosSystem i.e. useful to make self available
 , machines ? { } # allows to include machine-specific modules i.e. machines.${name} = { ... }
@@ -18,9 +18,12 @@ let
     (name: _:
       nixpkgs.lib.nixosSystem {
         modules = [
-          clan.nixosModules.clanCore
+          self.nixosModules.clanCore
           (machineSettings name)
           (machines.${name} or { })
+          { clanCore.clanDir = directory; }
+          # TODO: remove this once we have a hardware-config mechanism
+          { nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux"; }
         ];
         specialArgs = specialArgs;
       })