anchor.diff: -{ stdenv, fetchurl, erlang, rebar }:
  +{ stdenv, fetchurl, erlang, rebar, makeWrapper, coreutils }:
   
   stdenv.mkDerivation {
     name = "elixir-0.10.1";
  
positive.code:     substituteInPlace Makefile \
        --replace '$(shell echo `pwd`/rebar)' ${rebar}/bin/rebar \
        --replace "/usr/local" $out
    '';
  
    meta = {
  
negative.code:     sha256 = "0gfr2bz3mw7ag9z2wb2g22n2vlyrp8dwy78fj9zi52kzl5w3vc3w";
    };
  
    buildInputs = [ erlang rebar makeWrapper ];
  
    preBuild = ''
      substituteInPlace rebar \
  