Install seaweedfs from unstable on compute nodes.

flake.nix

@@ -6,13 +6,22 @@
     deploy-rs.inputs.nixpkgs.follows = "nixpkgs";
     impermanence.url = "github:nix-community/impermanence";
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
+    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
   };
 
-  outputs = { self, nixpkgs, deploy-rs, ... }@inputs:
+  outputs = { self, nixpkgs, nixpkgs-unstable, deploy-rs, ... }@inputs:
     let
       inherit (self);
+      system = "x86_64-linux";
+
+      overlay-unstable = final: prev: {
+        unstable = nixpkgs-unstable.legacyPackages.${prev.system};
+      };
+
       mkNixos = modules: nixpkgs.lib.nixosSystem {
-        inherit modules;
+        modules = [
+          ({ config, pkgs, ... }: { nixpkgs.overlays = [ overlay-unstable ]; })
+        ] ++ modules;
         specialArgs = { inherit inputs self; };
       };
     in {