---
title: "Chapter 4: Adding an overlay"
date: 2023-09-15
weight: 4
---

NOTE: We shouldn't be instructing users to use an overlay to replace packages in
`bsc.` until we have determined if we move them to the root attribute set
first!

```nix
{
  inputs.jungle.url = "jungle";
  nixConfig.bash-prompt = "\[nix-develop\]$ ";

  outputs = { self, jungle }:  
  let
    pkgs = jungle.outputs.packages.x86_64-linux;
    ovniDebug = pkgs.bsc.ovni.override { enableDebug = true; };
  in {
    devShells.x86_64-linux.default = pkgs.mkShell rec {
      pname = "my-shell";
      buildInputs = with pkgs.bsc; [
        ovniDebug osumb sonar
      ];
    };
  };
}
```