Try and fix bundix issues

flake.nix

@@ -6,19 +6,29 @@
   outputs = { self, nixpkgs }:
   let
     system = "x86_64-linux";
+    rubyVer = "ruby_3_1";
+    bundlerEnv = pkgs: ruby: pkgs.bundlerEnv {
+      pname = "danbooru";
+      inherit ruby;
+      gemdir = ./.;
+    };
+    overlay = final: prev: rec {
+      ruby = final.${rubyVer};
+      bundler = prev.bundler.override { inherit ruby; };
+      # Rev with Ruby 3 compat
+      bundix = (prev.bundix.override { inherit bundler; }).overrideAttrs (prev: {
+        src = final.fetchFromGitHub {
+          owner = "nix-community";
+          repo = "bundix";
+          rev = "3d7820efdd77281234182a9b813c2895ef49ae1f";
+          sha256 = "sha256-0CMDJR3xfewNuDthm3fEh6UPeRH9PURYxJ0PI1WPv4U=";
+        };
+      });
+      danbooru = bundlerEnv final ruby;
+    };
     pkgs = (import nixpkgs {
       inherit system;
-      config = {
-        packageOverrides = pkgs: rec {
-          ruby = pkgs.ruby_3_1;
-          bundler = pkgs.bundler.override {
-            inherit ruby;
-          };
-          bundix = pkgs.bundix.override {
-            inherit bundler;
-          };
-        };
-      };
+      overlays = [ overlay ];
     });
   in {
     devShells.${system} = {
@@ -41,7 +51,7 @@
     let
       gems = pkgs.bundlerEnv {
         name = "danbooru";
-        rubt = pkgs.ruby;
+        ruby = pkgs.ruby;
         gemdir = ./.;
       };
     in pkgs.stdenv.mkDerivation {