?

flake.nix

@@ -5,15 +5,19 @@
     self,
     nixpkgs,
   }: let
-    system = "aarch64-darwin"; # Use "x86_64-darwin" for Intel
+    system = "aarch64-darwin";
     pkgs = nixpkgs.legacyPackages.${system};
   in {
     devShells.${system}.default = pkgs.mkShell {
+      # pkg-config is needed for CMake to "see" the library
+      nativeBuildInputs = [pkgs.pkg-config];
       buildInputs = [pkgs.libjpeg_turbo];
 
       shellHook = ''
+        export PKG_CONFIG_PATH="${pkgs.libjpeg_turbo.dev}/lib/pkgconfig:$PKG_CONFIG_PATH"
         export C_INCLUDE_PATH="${pkgs.libjpeg_turbo.dev}/include:$C_INCLUDE_PATH"
         export LIBRARY_PATH="${pkgs.libjpeg_turbo}/lib:$LIBRARY_PATH"
+        echo "✅ Environment ready: libturbojpeg and pkg-config loaded."
       '';
     };
   };