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