working nixos overlay

config.nix

@@ -1,10 +1,12 @@
 let sources = import ./nix/sources.nix;
 in
   {
+    allowUnfree = true;
     overlays = [
       (import sources.nixpkgs-wayland)
       (import sources.nixpkgs-mozilla)
       (import sources.emacs-overlay)
+      (import ./nixos/overlay.nix)
       (import ./nix/.config/nixpkgs/overlays/01-backports.nix)
       (import ./nix/.config/nixpkgs/overlays/02-extrapkgs.nix)
       (import ./nix/.config/nixpkgs/overlays/03-customizations.nix)

default.nix

@@ -0,0 +1,3 @@
+let sources = import ./nix/sources.nix;
+in
+import sources.nixpkgs (import ./config.nix)

nixos/logical/zazu.nix

@@ -1,5 +1,5 @@
 # Edit this configuration file to define what should be installed on your system.  Help is available in the configuration.nix(5) man page and in the NixOS manual (accessible by running ‘nixos-help’).
-let sources = import ../nix/sources.nix; in
+let sources = import ../../nix/sources.nix; in
 { config, lib, pkgs, ... }:
 
 {

nixos/overlay.nix

@@ -0,0 +1,32 @@
+let 
+  names = [ "pennyworth" "jarvis" "blackadder" "woodhouse" "frumar" "zazu" ];
+in
+pkgs: super: {
+  yorick = rec {
+    nixos =
+      configuration: extraArgs:
+      let
+        c = import (pkgs.path + "/nixos/lib/eval-config.nix") {
+          inherit (pkgs.stdenv.hostPlatform) system;
+          inherit extraArgs;
+          modules =
+            [(
+              { lib, ... }: {
+                config.nixpkgs.pkgs = lib.mkDefault pkgs;
+              }
+            )] ++ (
+              if builtins.isList configuration
+              then configuration
+              else [configuration]
+            );
+        };
+      in
+        c.config.system.build // c;
+  };
+  yorick.machine = pkgs.lib.genAttrs names (name: nixos [
+    ./roles
+    (./logical + "/${name}.nix")
+  ] {
+    inherit name;
+  });
+}

nixos/physical/3950x.nix

@@ -1,5 +1,5 @@
 { config, pkgs, lib, ... }:
-let sources = import ../nix/sources.nix; 
+let sources = import ../../nix/sources.nix; 
 in
 {
   imports =

nixos/physical/fractal.nix

@@ -1,5 +1,5 @@
 { config, lib, pkgs, ... }:
-let sources = import ../nix/sources.nix;
+let sources = import ../../nix/sources.nix;
 in
 {
   imports =

nixos/physical/nuc.nix

@@ -1,5 +1,5 @@
 { config, lib, pkgs, modulesPath, ... }:
-let sources = import ../nix/sources.nix; 
+let sources = import ../../nix/sources.nix; 
 in
 {
 

nixos/physical/xps9360.nix

@@ -1,5 +1,5 @@
 { config, lib, pkgs, ... }:
-let sources = import ../nix/sources.nix;
+let sources = import ../../nix/sources.nix;
 in
 {
   imports = [

nixos/roles/workstation.nix

@@ -1,6 +1,5 @@
 { config, lib, pkgs, ... }:
 let
-  sources = import ../nix/sources.nix;
   nixNetrcFile = pkgs.runCommand "nix-netrc-file"
 { hostname = "cache.lumi.guide";
   username = "lumi";
@@ -17,7 +16,6 @@ in
     ./graphical.nix
   ];
 
-  nixpkgs.overlays = [ (import sources.nixpkgs-wayland) ];
   users.extraUsers.yorick.extraGroups = [ "input" "wireshark" "dialout" ];
   services.printing = {
     enable = true;

nixos/services/email.nix

@@ -1,6 +1,6 @@
 { config, pkgs, lib, ... }:
 let
-  sources = import ../nix/sources.nix;
+  sources = import ../../nix/sources.nix;
 in
 {
   imports = [