self: super:
let
  newsrc = super.pkgs.lib.fetchFromGitHub {
    owner = "neovim";
    repo = "neovim";
    rev = "v0.4.0";
    sha256 = "07ncvgp6xfhiwc6hd7qf7zk28n3yj47p26qj1ji29vqkwnk28y3s";
  };
in
{
  nneovim = super.neovim.overrideAttrs (oldAttrs: rec { src = newsrc; });
}