Adding unstable to pkgs.unstable and try apply it at runtime

base.nix

@@ -36,16 +36,24 @@
 
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
 
-  /* This makes commandline tools like
-  ** nix run nixpkgs#hello
-  ** and nix-shell -p hello
-  ** use the same channel the system
-  ** was built with
-  */
+  # This makes commandline tools like nix run nixpkgs#hello
+  # and nix-shell -p hello use the same channel the system was built with
   nix.registry = {
     nixpkgs.flake = inputs.nixpkgs;
   };
-  nix.nixPath = [ "nixpkgs=${inputs.nixpkgs}" ];
+  nix.nixPath = [
+    "nixpkgs=${inputs.nixpkgs}"
+    "nixpkgs-overlays=${./overlays-compat}/"
+  ];
+
+  # Allows access to nixpkgs-unstable via pkgs.unstable
+  nixpkgs.overlays = let
+    unstable-overlay = final: prev: {
+      unstable = inputs.unstable.legacyPackages.${prev.system};
+    };
+  in [
+    unstable-overlay
+  ];
 
   environment.systemPackages = with pkgs; [
     file

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "matrix-next": {
       "locked": {
-        "lastModified": 1671009204,
-        "narHash": "sha256-gqA9po/KmHyh44XYqv/LfFJ1+MGufhaaD6DhDqBeaF8=",
+        "lastModified": 1671480255,
+        "narHash": "sha256-06G6xYTFPVuvmN/k2QDeBk9XIp4LDxEKWRL3aLAFFNo=",
         "owner": "dali99",
         "repo": "nixos-matrix-modules",
-        "rev": "43dbc17526576cb8e0980cef51c48b6598f97550",
+        "rev": "f42306e0a2df064f1beb6dfcc1776ea33e7ae9df",
         "type": "github"
       },
       "original": {
@@ -18,11 +18,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1670946965,
-        "narHash": "sha256-PDJfKgK/aSV3ISnD1TbKpLPW85LO/AQI73yQjbwribA=",
+        "lastModified": 1671445885,
+        "narHash": "sha256-oDCTgQiqr3y62NrU+viFCYXKln24wgUdYaf4ynXRPgI=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "265caf30fa0a5148395b62777389b57eb0a537fd",
+        "rev": "d3cf188b498a7dc936de67254ba2fdafcf5a1368",
         "type": "github"
       },
       "original": {
@@ -34,11 +34,11 @@
     },
     "nixpkgs-stable": {
       "locked": {
-        "lastModified": 1670146390,
-        "narHash": "sha256-XrEoDpuloRHHbUkbPnhF2bQ0uwHllXq3NHxtuVe/QK4=",
+        "lastModified": 1671459584,
+        "narHash": "sha256-6wRK7xmeHfClJ0ICOkax1avLZVGTDqBodQlkl/opccY=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "86370507cb20c905800527539fc049a2bf09c667",
+        "rev": "87b58217c9a05edcf7630b9be32570f889217aef",
         "type": "github"
       },
       "original": {
@@ -64,11 +64,11 @@
         "nixpkgs-stable": "nixpkgs-stable"
       },
       "locked": {
-        "lastModified": 1670149631,
-        "narHash": "sha256-rwmtlxx45PvOeZNP51wql/cWjY3rqzIR3Oj2Y+V7jM0=",
+        "lastModified": 1671472949,
+        "narHash": "sha256-9iHSGpljCX+RypahQssBXPwkru9onfKfceCTeVrMpH4=",
         "owner": "Mic92",
         "repo": "sops-nix",
-        "rev": "da98a111623101c64474a14983d83dad8f09f93d",
+        "rev": "32840f16ffa0856cdf9503a8658f2dd42bf70342",
         "type": "github"
       },
       "original": {
@@ -79,11 +79,11 @@
     },
     "unstable": {
       "locked": {
-        "lastModified": 1670918062,
-        "narHash": "sha256-iOhkyBYUU9Jfkk0lvI4ahpjyrTsLXj9uyJWwmjKg+gg=",
+        "lastModified": 1671442489,
+        "narHash": "sha256-pSCuSrG+XxWCs5IZ90eKIxDIZy4rM22YSFMRZ/fiixc=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "84575b0bd882be979516f4fecfe4d7c8de8f6a92",
+        "rev": "ff07b107adeda2164b29f8feb4a86ed012854dfb",
         "type": "github"
       },
       "original": {

flake.nix

@@ -22,8 +22,9 @@
     nixosConfigurations = {
       jokum = nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";
-        specialArgs = { inherit unstable inputs; };
+        specialArgs = { inherit inputs; };
         modules = [
+          ./base.nix
           ./hosts/jokum/configuration.nix
           sops-nix.nixosModules.sops
 
@@ -32,8 +33,9 @@
       };
       ildkule = nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";
-        specialArgs = { inherit unstable inputs; };
+        specialArgs = { inherit inputs; };
         modules = [
+          ./base.nix
           ./hosts/ildkule/configuration.nix
           sops-nix.nixosModules.sops
         ];

hosts/jokum/configuration.nix

@@ -4,7 +4,6 @@
       # Include the results of the hardware scan.
       ./hardware-configuration.nix
 
-      ../../base.nix
       # Users can just import any configuration they want even for non-user things. Improve the users/default.nix to just load some specific attributes if this isn't wanted
 
       ../../misc/rust-motd.nix

overlays-compat/overlays.nix

@@ -0,0 +1,8 @@
+self: super:
+with super.lib;
+let
+  # Load the system config and get the `nixpkgs.overlays` option
+  overlays = (import <nixpkgs/nixos> { }).config.nixpkgs.overlays;
+in
+  # Apply all overlays to the input of the current "main" overlay
+  foldl' (flip extends) (_: super) overlays self