anchor.diff:  { stdenv
   , fetchurl
  +, lib
   
   , giflib
   , libjpeg
  
positive.code:   ];
  
    configureFlags = [
      (enFlag "programs" programs null)
      (wtFlag "zlib" (zlib != null) null)
      (wtFlag "libpng" (libpng != null) null)
      (wtFlag "jpeg" (openjpeg != null) null)
      (wtFlag "giflib" (giflib != null) null)
      (wtFlag "libtiff" (libtiff != null) null)
      (wtFlag "libwebp" (libwebp != null) null)
      (wtFlag "libopenjpeg" (openjpeg != null) null)
    ];
  
    meta = with stdenv.lib; {
      description = "Image processing and analysis library";
      homepage = http://www.leptonica.org/;
      # Its own license: http://www.leptonica.org/about-the-license.html
  
negative.code: }:
  
  let
    inherit (lib)
      boolEn
      boolWt;
  in
  stdenv.mkDerivation rec {
    name = "leptonica-1.73";
  
    src = fetchurl {
      url = "http://www.leptonica.org/source/${name}.tar.gz";
      multihash = "QmdsTL6sLfcSxH1ZPSbhwt6KNcYVDrQRbcqCT3rsGhbKgp";
      sha256 = "19e4335c674e7b78af9338d5382cc5266f34a62d4ce533d860af48eaa859afc1";
    };
  
  