anchor.diff:    src = fetchurl {
       url = "mirror://sourceforge/libjpeg-turbo/${version}/${name}.tar.gz";
       hashOutput = false;
  -    sha256 = "778876105d0d316203c928fd2a0374c8c01f755d0a00b12a1c8934aeccff8868";
  +    sha256 = "e5f86cec31df1d39596e0cca619ab1b01f99025a27dafdfc97a30f3a12f866ff";
     };
   
     nativeBuildInputs = [
  
positive.code: }:
  
  let
    version = "2.0.0";
  in
  stdenv.mkDerivation rec {
    name = "libjpeg-turbo-${version}";
  
negative.code: 
      srcVerification = fetchurl {
        failEarly = true;
        inherit (src)
          urls
          outputHash
          outputHashAlgo;
        fullOpts = {
          pgpsigUrls = map (n: "${n}.sig") src.urls;
          pgpKeyFingerprint = "7D62 93CC 6378 786E 1B5C  4968 85C7 044E 033F DE16";
        };
      };
    };
  
  