anchor.diff:  
   let
     pname = "icu4c";
  -  version = "57.1";
  +  version = "58.2";
   in
   stdenv.mkDerivation ({
     name = pname + "-" + version;
  
positive.code:   '';
  
    patches = [
      (fetchpatch {
        url = "https://sources.debian.net/data/main/i/icu/57.1-5/debian/patches/CVE-2014-6585.patch";
        sha256 = "1s8kqax444pqf5chwxvgsx1n1dx7v74h34fqh08fyq57mcjnpj4d";
      })
      (fetchpatch {
        url = "https://sources.debian.net/data/main/i/icu/57.1-5/debian/patches/CVE-2015-4760.patch";
        sha256 = "08gawyqbylk28i9pxv9vsw2drdpd6i97q0aml4nmv2xyb1ala0wp";
      })
      (fetchpatch {
        url = "https://sources.debian.net/data/main/i/icu/57.1-5/debian/patches/CVE-2016-0494.patch";
        sha256 = "1741s8lpmnizjprzk3xb7zkm5fznzgk8hhlrs8a338c18nalvxay";
      })
      (fetchpatch {
        url = "https://sources.debian.net/data/main/i/icu/57.1-5/debian/patches/CVE-2016-6293.patch";
        sha256 = "01h4xcss1vmsr60ijkv4lxsgvspwimyss61zp9nq4xd5i3kk1f4b";
      })
      (fetchpatch {
        url = "https://sources.debian.net/data/main/i/icu/57.1-5/debian/patches/CVE-2016-7415.patch";
        sha256 = "01d070h8d7rkj55ac8isr64m999bv5znc8vnxa7aajglsfidzs2r";
      })
    ];
  
    preConfigure = ''
  
negative.code:   src = fetchurl {
      url = "http://download.icu-project.org/files/${pname}/${version}/${pname}-"
        + (stdenv.lib.replaceChars ["."] ["_"] version) + "-src.tgz";
      sha256 = "036shcb3f8bm1lynhlsb4kpjm9s9c2vdiir01vg216rs2l8482ib";
    };
  
    outputs = [ "out" "dev" ];
  