Add darwin shim, fix setting names

darwin.nix

@@ -0,0 +1,7 @@
+{ system ? builtins.currentSystem
+, nixpkgs ? ./nixpkgs.nix
+, pkgs ? import nixpkgs { inherit system; }
+, lib ? pkgs.lib
+, ...
+}@args:
+import (import ./default.nix).inputs.darwin args

darwin/bootstrap.nix

@@ -2,20 +2,20 @@
 {
   # Nix configuration ------------------------------------------------------------------------------
 
-  nix.settings.binaryCaches = [
+  nix.settings.trusted-substituters = [
     "https://cache.nixos.org/"
     "https://hydra.iohk.io"
     "https://cache.iog.io"
     "https://nix-community.cachix.org"
     "https://mat.cachix.org"
   ];
-  nix.settings.binaryCachePublicKeys = [
+  nix.settings.trusted-public-keys = [
     "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
     "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ="
     "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
     "mat.cachix.org-1:AHqv9SoBEPKlJX2DDZQnjaMcvBAgpH1j8rw5USYDZno="
   ];
-  nix.settings.trustedUsers = [
+  nix.settings.trusted-users = [
     "@admin"
   ];
   nix.configureBuildUsers = true;

flake.nix

@@ -102,7 +102,10 @@
           {
             nixpkgs = nixpkgsConfig;
             # Hack to support legacy worklows that use `<nixpkgs>` etc.
-            nix.nixPath = { nixpkgs = "$HOME/dotfiles.nix/nixpkgs.nix"; };
+            nix.nixPath = {
+              nixpkgs = "$HOME/dotfiles.nix/nixpkgs.nix";
+              darwin = "$HOME/dotfiles.nix/darwin.nix";
+            };
             # `home-manager` config
             users.users.${primaryUser}.home = "/Users/${primaryUser}";
             home-manager.useGlobalPkgs = true;
@@ -134,8 +137,8 @@
               networking.knownNetworkServices = [
                 "Wi-Fi"
               ];
-              nix.settings.buildCores = 2;
-              nix.settings.maxJobs = 4;
+              nix.settings.cores = 2;
+              nix.settings.max-jobs = 4;
 
               environment.systemPackages = with pkgs; [
                 vscodium
@@ -163,8 +166,8 @@
               networking.knownNetworkServices = [
                 "Wi-Fi"
               ];
-              nix.settings.buildCores = 2;
-              nix.settings.maxJobs = 5;
+              nix.buildCores = 2;
+              nix.maxJobs = 5;
 
               games.enable = false;
               environment.systemPackages = with pkgs; [