Add a stable branch to my flake.nix to still use broken packages if broken on unstable

flake.lock

@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1762964643,
-        "narHash": "sha256-RYHN8O/Aja59XDji6WSJZPkJpYVUfpSkyH+PEupBJqM=",
+        "lastModified": 1763228015,
+        "narHash": "sha256-1rYieMVUyZ3kK/cBIr8mOusxrOEJ1/+2MsOg0oJ7b3A=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "827f2a23373a774a8805f84ca5344654c31f354b",
+        "rev": "96156a9e86281c4bfc451236bc2ddfe4317e6f39",
         "type": "github"
       },
       "original": {
@@ -52,11 +52,28 @@
         "type": "github"
       }
     },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1763049705,
+        "narHash": "sha256-A5LS0AJZ1yDPTa2fHxufZN++n8MCmtgrJDtxFxrH4S8=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "3acb677ea67d4c6218f33de0db0955f116b7588c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-25.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "home-manager": "home-manager",
         "nixos-hardware": "nixos-hardware",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-stable": "nixpkgs-stable"
       }
     }
   },

flake.nix

@@ -3,6 +3,7 @@
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    nixpkgs-stable.url = "github:nixos/nixpkgs/nixos-25.05";
 
     home-manager = {
       url = "github:nix-community/home-manager";
@@ -13,18 +14,26 @@
   };
 
   outputs =
-    { nixpkgs, home-manager, nixos-hardware, ... }:
+    { nixpkgs, nixpkgs-stable, home-manager, nixos-hardware, ... }:
+    let
+      system = "x86_64-linux";
+    in
     {
-      nixosConfigurations.TARS = nixpkgs.lib.nixosSystem {
-        system = "x86_64-linux";
+      nixosConfigurations = {
+        TARS = nixpkgs.lib.nixosSystem {
+        inherit system;
         modules = [
           ./nixos/configuration.nix
           nixos-hardware.nixosModules.framework-amd-ai-300-series         
         ];
+        specialArgs = {
+          pkgs-stable = nixpkgs-stable.legacyPackages.${system};
+        };
+        };
       };
 
       homeConfigurations.zeph = home-manager.lib.homeManagerConfiguration {
-        pkgs = nixpkgs.legacyPackages."x86_64-linux";
+        pkgs = nixpkgs.legacyPackages.${system};
         modules = [ ./home-manager/home.nix ];
       };
 

nixos/pkgs.nix

@@ -1,5 +1,5 @@
-{ pkgs, lib, config, ... }: {
-  environment.systemPackages = with pkgs; [
+{ pkgs, pkgs-stable, lib, config, ... }: {
+  environment.systemPackages = (with pkgs; [
     # Editors
     helix
     vim
@@ -40,10 +40,8 @@
     starship
     home-manager
     capitaine-cursors-themed
-    # adwaita-icon-theme
     libsecret
     lsd
-    # protonvpn-gui
     wireguard-tools
 
     # Internet
@@ -67,7 +65,11 @@
     hyprshot
     mako
     swayosd
-  ];
+  ])
+  ++
+  (with pkgs-stable; [
+    protonvpn-gui
+  ]);
 
   # Unfree pkgs
   nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [