self: super: {
  hydra-unstable = super.hydra-unstable.overrideAttrs (oldAttrs: rec {
    patches = (oldAttrs.patches or []) ++ map super.fetchpatch [
      { meta.description = "Fix unhelpful error messages in aggregate jobs.";
        url = "https://github.com/NixOS/hydra/pull/825.diff";
        sha256 = "sha256-L8SWhPHOxuzYpeeu6WuxXKsWo6e687IYIrxzwMJQses";
      }
    ];
  });
}