use pkgs.stdenv.hostPlatform

nix/home-manager/flake.nix

@@ -57,10 +57,6 @@
           nix-index-database.hmModules.nix-index
           ./home.nix
         ];
-
-        extraSpecialArgs = {
-          system = system;
-        };
       }
     );
   in {

nix/home-manager/home.nix

@@ -1,15 +1,16 @@
 {
   config,
   pkgs,
-  system,
   ...
-}: {
+}: let
+  inherit (pkgs.stdenv.hostPlatform) isDarwin isLinux;
+in {
   # Home Manager needs a bit of information about you and the paths it should
   # manage.
   home.username = "acicchetti";
 
   home.homeDirectory =
-    if "${system}" == "aarch64-darwin"
+    if isDarwin
     then "/Users/acicchetti"
     else "/home/acicchetti";
 

nix/home-manager/modules/packages/default.nix

@@ -2,11 +2,11 @@
   pkgs,
   lib,
   config,
-  system,
   ...
 }: let
+  inherit (pkgs.stdenv.hostPlatform) isDarwin isLinux;
   systemSpecificPackages =
-    if "${system}" != "aarch64-darwin"
+    if isLinux
     # include gping because of open bug
     then [pkgs.zsh pkgs.racket pkgs.gping pkgs.mold]
     else [];