anchor.diff:        "je_cv_thp=no"
       ]
     ;
  +
  +  NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin "-Wno-error=array-bounds";
   
     doCheck = true;
   
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "jemalloc";
    version = "5.2.1";
  
    src = fetchurl {
      url = "https://github.com/jemalloc/jemalloc/releases/download/${version}/${pname}-${version}.tar.bz2";
      sha256 = "1xl7z0vwbn5iycg7amka9jd6hxd8nmfk7nahi4p9w2bnw9f0wcrl";
    };
  
    patches = [
      # workaround https://github.com/jemalloc/jemalloc/issues/2091
      (fetchpatch {
        url = "https://github.com/jemalloc/jemalloc/commit/3b4a03b92b2e415415a08f0150fdb9eeb659cd52.diff";
        sha256 = "sha256-6AYtADREhfj93ZLk9xnXtjc6vHDU0EKLLOvLd6YdJeI=";
      })
    ];
  
    # see the comment on stripPrefix
    configureFlags = []
  
negative.code: { lib
  , stdenv
  , fetchurl
  # By default, jemalloc puts a je_ prefix onto all its symbols on OSX, which
  # then stops downstream builds (mariadb in particular) from detecting it. This
  # option should remove the prefix and give us a working jemalloc.
  