Inventory: only apply if settings.json exists

lib/build-clan/default.nix

@@ -78,7 +78,9 @@ let
 
         # Will be deprecated
         {
-          machines = lib.mapAttrs (
+          machines =
+            lib.mapAttrs
+              (
                 name: _:
                 # Use mkForce to make sure users migrate to the inventory system.
                 # When the settings.json exists the evaluation will print the deprecation warning.
@@ -86,7 +88,12 @@ let
                   inherit name;
                   system = (machineSettings name).nixpkgs.hostSystem or null;
                 }
-          ) machinesDirs;
+              )
+              (
+                lib.filterAttrs (
+                  machineName: _: builtins.pathExists "${directory}/machines/${machineName}/settings.json"
+                ) machinesDirs
+              );
         }
 
         # Deprecated interface

templates/flake-parts/flake.nix

@@ -99,7 +99,6 @@
               */
               # clan.core.networking.zerotier.networkId = builtins.readFile ../jon/facts/zerotier-network-id;
             };
-
           };
       };
       perSystem =