monolith: install mesa 26

flake.lock

@@ -618,6 +618,21 @@
         "type": "github"
       }
     },
+    "nixpkgs-mesa-26": {
+      "locked": {
+        "lastModified": 1770837954,
+        "narHash": "sha256-B9rn+KSP/+lgM7j406sDIapS1IedxgACFdiRHzMTzVU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "157721757fca10d3f26d11ace9883f1f0b0bccef",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "rev": "157721757fca10d3f26d11ace9883f1f0b0bccef",
+        "type": "indirect"
+      }
+    },
     "nixpkgs-unstable": {
       "locked": {
         "lastModified": 1770562336,
@@ -790,6 +805,7 @@
         "nix-index-database": "nix-index-database",
         "nixos-mailserver": "nixos-mailserver",
         "nixpkgs": "nixpkgs_5",
+        "nixpkgs-mesa-26": "nixpkgs-mesa-26",
         "nixpkgs-unstable": "nixpkgs-unstable",
         "plymouth-themes": "plymouth-themes",
         "ranger-icons": "ranger-icons",

flake.nix

@@ -4,6 +4,8 @@
     nixpkgs.url = "nixpkgs/nixos-25.11";
     nixpkgs-unstable.url = "nixpkgs/nixos-unstable";
 
+    nixpkgs-mesa-26.url = "nixpkgs/157721757fca10d3f26d11ace9883f1f0b0bccef";
+
     home-manager.url = "github:nix-community/home-manager/release-25.11";
     home-manager.inputs.nixpkgs.follows = "nixpkgs";
 

hosts/monolith/amdgpu.nix

@@ -12,9 +12,12 @@
   #   };
   # };
 
+  hardware.graphics.package = pkgs.pkgs-mesa-26.mesa;
+
   hardware.graphics.enable32Bit = true;
 
   hardware.graphics.extraPackages = with pkgs; [
-    libva
+    # libva needs to match `hardware.graphics.package`
+    pkgs-mesa-26.libva
   ];
 }

overlays/default.nix

@@ -14,6 +14,7 @@ rec {
 
   unstable = final: prev: {
     unstable = import inputs.nixpkgs-unstable { inherit (final) system config; };
+    pkgs-mesa-26 = import inputs.nixpkgs-mesa-26 { inherit (final) system config; };
   };
 
   themes = (