Add Unstable Package Support

flake.lock

@@ -69,10 +69,27 @@
         "type": "github"
       }
     },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1690367991,
+        "narHash": "sha256-2VwOn1l8y6+cu7zjNE8MgeGJNNz1eat1HwHrINeogFA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "c9cf0708f00fbe553319258e48ca89ff9a413703",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "nix-matlab": "nix-matlab",
         "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable",
         "sops-nix": "sops-nix"
       }
     },

flake.nix

@@ -3,6 +3,9 @@
     nixpkgs = {
       url = "github:NixOS/nixpkgs/release-23.05";
     };
+    nixpkgs-unstable = {
+      url = "github:NixOS/nixpkgs/nixos-unstable";
+    };
     sops-nix = {
       url = "github:Mic92/sops-nix";
       # Follow the system nixpkgs
@@ -14,7 +17,7 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
   };
-  outputs = { self, nixpkgs, sops-nix, nix-matlab }@attrs: let 
+  outputs = { self, nixpkgs, nixpkgs-unstable, sops-nix, nix-matlab }@attrs: let 
     system = "x86_64-linux";
     unfree-overlay = final: prev: {
       unfree = import nixpkgs {
@@ -22,6 +25,15 @@
         config.allowUnfree = true;
       };
     };
+    unstable-overlay = final: prev: { 
+      unstable = import nixpkgs-unstable { inherit system; } ;
+    };
+    unstable-unfree-overlay = final: prev: {
+      unstable-unfree = import nixpkgs-unstable {
+        inherit system;
+        config.allowUnfree = true;
+      };
+    };
     applyOverlays = overlays: ({...}:{ nixpkgs.overlays = overlays; });
   in {
     nixosConfigurations.kcnhub = nixpkgs.lib.nixosSystem {