anchor.diff:  let
     version = "5.1.0";
   
  -  inherit (stdenv.lib)
  +  inherit (lib)
       optionals;
   in
   stdenv.mkDerivation rec {
  
positive.code: { stdenv
  , fetchurl
  
  , functionPrefix ? null
  }:
  
negative.code: 
    disableStatic = false;
  
    meta = with lib; {
      homepage = http://www.canonware.com/jemalloc/index.html;
      description = "General purpose malloc(3) implementation";
      license = licenses.bsd2;
  