Adapt for current wat

flake.nix

@@ -12,9 +12,12 @@
   };
 
   outputs = flakes: flakes.wat.lib.mkWatRepo flakes ({ findModules, findMachines, ... }: rec {
+    loadOverlays = [ outputs.overlay ];
     loadModules = outputs.nixosModules;
     outputs = {
 
+      overlay = import ./pkgs;
+
       nixosModules = findModules ["example"] ./modules;
 
       nixosConfigurations = findMachines ./machines;

machines/foobar/default.nix

@@ -20,4 +20,7 @@ mkMachine {
     specialExtraPackages = with pkgs; [ htop ];
   };
 
+  #install some example packages
+  environment.systemPackages = with pkgs; [ my-hello ];
+
 })

pkgs/default.nix

+final: prev:
+with final.lib;
+
+{
+
+  my-hello = final.hello.overrideAttrs (orig: { pname = "my-${orig.pname}"; });
+
+}