Setup more package details

flake.nix

@@ -9,7 +9,6 @@
   outputs = { self, nixpkgs, flake-utils, ... }:
     flake-utils.lib.eachDefaultSystem (system:
       let
-        overlays = [];
         pkgs = nixpkgs.legacyPackages.${system};
         
         # package/executable name
@@ -40,11 +39,11 @@
       in
       {
         # Used by `nix build` & `nix run` (prod exe)
-        defaultPackage = project false;
+        packages.default = project false;
 
-        defaultApp = {
+        apps.default = {
           type = "app";
-          program = "${self.defaultPackage.${system}}/bin/${execName}";
+          program = "${self.packages.${system}.default}/bin/${execName}";
         };
 
         # Used by `nix develop` (dev shell)

snake.cabal

@@ -7,7 +7,10 @@ license:       MIT
 build-type:    Simple
 
 executable snake
+  hs-source-dirs: src
   main-is:        Main.hs
-  default-language: GHC2021
-  other-modules:
-  build-depends: dunai
+  default-language:   GHC2021
+  default-extensions: Arrows
+  build-depends: base,
+                 dunai,
+                 gloss