flake: add overlays and minimal devShell

inspired by 1cbeaa156b/profiles/base/default.nix

common/packages.nix

@@ -1,6 +1,8 @@
-{ pkgs, config, ... }:
+{ lib, pkgs, config, ... }:
 
 { 
+  # take overlays from flake
+  nixpkgs.overlays = lib.attrValues config.inputInjection.flake-inputs.self.overlays;
   # List packages installed in system profile.
   environment.systemPackages = with pkgs; [
     wget

flake.nix

@@ -26,10 +26,10 @@
   };
 
   outputs = 
-  { self, nixpkgs, nur, lanzaboote, flake-utils, home-manager, ... }@inputs: 
+  { self, nixpkgs, nur, lanzaboote, utils, home-manager, ... }@inputs: 
   let
     # FIXME: allow different systems
-    systems = flake-utils.lib.system;
+    systems = utils.lib.system;
     # necessary to make the top-level inputs available to system configuration
     # inspired by https://jade.fyi/blog/flakes-arent-real/
     inputInjection = {pkgs, lib, ...}: {
@@ -74,10 +74,24 @@
     };
   in
   {
+    overlays.default = import ./packages;
     nixosConfigurations = {
       thinknix = mkSystem systems.x86_64-linux [ ./hosts/thinknix inputs.nixos-hardware.nixosModules.lenovo-thinkpad-t440s lanzaboote.nixosModules.lanzaboote ];
       framenix = mkSystem systems.x86_64-linux [ ./hosts/framenix inputs.nixos-hardware.nixosModules.framework-13-7040-amd lanzaboote.nixosModules.lanzaboote ];
     };
     homeConfigurations.spiollinux = mkHomeManager "spiollinux" "spiollinux" systems.x86_64-linux;
-  };
+  } // utils.lib.eachDefaultSystem(system:
+    let
+      nixpkgs = import inputs.nixpkgs {
+        inherit system;
+        overlays = nixpkgs.lib.attrValues self.overlays;
+      };
+      pkgs = inputs.nixpkgs.legacyPackages.${system};
+    in {
+      devShells.default = pkgs.mkShell {
+        buildInputs = [];
+      };
+      # expose nixpkgs with overlay; TODO: figure out role of config
+      #legacyPackages = nixpkgs;
+    });
 }

packages/default.nix

@@ -0,0 +1,2 @@
+final: prev: {
+}