feat(nix): lets try the Lix fork, the performance enhancements sound …

…quite good

flake.nix

@@ -105,6 +105,18 @@
       inputs.pre-commit-hooks-nix.follows = "pre-commit-hooks";
     };
 
+    # The Lix package manager (fork of Nix)
+    lix = {
+      url = "git+https://[email protected]/lix-project/lix?ref=refs/tags/2.90-beta.1";
+      flake = false;
+    };
+    lix-module = {
+      url = "git+https://git.lix.systems/lix-project/nixos-module";
+      inputs.flake-utils.follows = "chaotic-nyx/flake-utils";
+      inputs.lix.follows = "lix";
+      inputs.nixpkgs.follows = "chaotic-nyx/nixpkgs";
+    };
+
     # Nix gaming-related packages and modules
     nix-gaming = {
       url = "github:fufexan/nix-gaming";

nixos/flake-module.nix

@@ -10,6 +10,7 @@
       inputs.disko.nixosModules.disko
       inputs.hosts.nixosModule
       inputs.lanzaboote.nixosModules.lanzaboote
+      inputs.lix-module.nixosModules.default
       inputs.sops-nix.nixosModules.sops
       inputs.spicetify-nix.nixosModule
     ];

nixos/modules/nix.nix

@@ -94,10 +94,7 @@ in {
       '';
 
       # Make use of nix-super if it is enabled, else use latest available
-      package =
-        if cfgSuper.enable
-        then pkgs.nixSuper
-        else pkgs.nixVersions.nix_2_22;
+      package = lib.mkIf cfgSuper.enable pkgs.nixSuper;
 
       # Nix.conf settings
       settings = {
@@ -107,6 +104,9 @@ in {
         # Test out ca-derivations (https://nixos.wiki/wiki/Ca-derivations)
         experimental-features = ["ca-derivations"];
 
+        # Lix cache
+        extra-substituters = ["https://cache.lix.systems"];
+
         # For direnv GC roots
         keep-derivations = true;
         keep-outputs = true;
@@ -142,6 +142,8 @@ in {
           "https://pre-commit-hooks.cachix.org" # pre commit hooks
           "https://cache.garnix.io" # extra things here and there
         ];
+
+        trusted-public-keys = ["cache.lix.systems:aBnZUw8zA7H35Cz2RyKFVs3H4PlGTLawyY5KRbvJR8o="];
       };
     };