maybe working nix pkg

flake.nix

···
+{
+  description = "blu's neovim config";
+
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+
+  outputs = { self, nixpkgs }:
+    let
+      systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" ];
+      forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f nixpkgs.legacyPackages.${system});
+    in {
+      packages = forAllSystems (pkgs: {
+        default = pkgs.neovim.override {
+          configure = {
+            customRC = ''
+              set runtimepath+=${self}
+              luafile ${self}/init.lua
+            '';
+          };
+        };
+      });
+
+      overlays.default = final: prev: {
+        blu-nvim = self.packages.${prev.system}.default;
+      };
+    };
+}