anchor.diff:    ];
   
     environment.systemPackages = with pkgs; [
  -    ((emacsPackagesGen emacsGcc).emacsWithPackages (epkgs: [
  -      epkgs.vterm
  -    ]))
  -    (neovim.override ({
  -      withNodeJs = true;
  -      vimAlias = true;
  -      viAlias = true;
  -    }))
       binutils
       cmake
       elixir
  +    emacsCustom
       erlang
       expect
       gcc
  
positive.code:     libtool
      m4
      ncurses.dev
      nim
      nodejs-10_x
      pipenv
  
negative.code: { pkgs, ... }:
  
  let
    emacsCustom = (pkgs.emacsPackagesGen pkgs.emacsGcc).emacsWithPackages (epkgs: [
      epkgs.vterm
    ]);
    neovimCustom = pkgs.neovim.override ({
      withNodeJs = true;
      vimAlias = true;
      viAlias = true;
    });
  in {
    # Emacs overlay
    nixpkgs.overlays = [
      (import (builtins.fetchTarball {
  