anchor.diff:  in
   assert mixNixDeps != { } -> mixFodDeps == null;
   stdenv.mkDerivation (overridable // {
  -  nativeBuildInputs = nativeBuildInputs ++ [ erlang hex elixir makeWrapper git ];
  +  # rg is used as a better grep to search for erlang references in the final release
  +  nativeBuildInputs = nativeBuildInputs ++ [ erlang hex elixir makeWrapper git ripgrep ];
     buildInputs = builtins.attrValues mixNixDeps;
   
     MIX_ENV = mixEnv;
  
positive.code: { stdenv, lib, elixir, erlang, findutils, hex, rebar3, fetchMixDeps, makeWrapper, git }:
  
  { pname
  , version
  
negative.code:     # removing unused erlang reference from resulting derivation to reduce
      # closure size
      if [ -e $out/erts-* ]; then
        echo "ERTS found in $out - removing references to erlang to reduce closure size"
        for file in $(rg "${erlang}/lib/erlang" "$out" --text --files-with-matches); do
          substituteInPlace "$file" --replace "${erlang}/lib/erlang" "$out"
        done
      fi
  