anchor.diff:  { stdenv
   , fetchurl
  +, lib
   
   , giflib
   , libjpeg
  
positive.code: }:
  
  let
    inherit (stdenv.lib)
      enFlag
      wtFlag;
  in
  
  stdenv.mkDerivation rec {
    name = "leptonica-1.73";
  
    src = fetchurl {
      url = "http://www.leptonica.org/source/${name}.tar.gz";
      sha256 = "19e4335c674e7b78af9338d5382cc5266f34a62d4ce533d860af48eaa859afc1";
    };
  
  
negative.code:   ];
  
    configureFlags = [
      "--${boolEn programs}-programs"
      "--${boolWt (zlib != null)}-zlib"
      "--${boolWt (libpng != null)}-libpng"
      "--${boolWt (openjpeg != null)}-jpeg"
      "--${boolWt (giflib != null)}-giflib"
      "--${boolWt (libtiff != null)}-libtiff"
      "--${boolWt (libwebp != null)}-libwebp"
      "--${boolWt (openjpeg != null)}-libopenjpeg"
    ];
  
    meta = with lib; {
      description = "Image processing and analysis library";
      homepage = http://www.leptonica.org/;
      # Its own license: http://www.leptonica.org/about-the-license.html
  