anchor.diff: -{ lib, stdenv, fetchurl, fetchpatch, fetchFromGitHub, cmake, pkgconfig, unzip
  -, zlib
  -, enableIpp ? false
  -, enableContrib ? false
  -, enablePython ? false, pythonPackages
  -, enableGtk2 ? false, gtk2
  -, enableGtk3 ? false, gtk3
  -, enableJPEG ? true, libjpeg
  -, enablePNG ? true, libpng
  -, enableTIFF ? true, libtiff
  -, enableWebP ? true, libwebp
  -, enableEXR ? true, openexr, ilmbase
  -, enableJPEG2K ? true, jasper
  -, enableFfmpeg ? false, ffmpeg
  +{ lib, stdenv, fetchurl, fetchpatch, fetchFromGitHub, cmake, pkgconfig, unzip, zlib
  +
  +, enableJPEG      ? true, libjpeg
  +, enablePNG       ? true, libpng
  +, enableTIFF      ? true, libtiff
  +, enableWebP      ? true, libwebp
  +, enableEXR       ? true, openexr, ilmbase
  +, enableJPEG2K    ? true, jasper
  +
  +, enableIpp       ? false
  +, enableContrib   ? false, protobuf3_1
  +, enablePython    ? false, pythonPackages
  +, enableGtk2      ? false, gtk2
  +, enableGtk3      ? false, gtk3
  +, enableFfmpeg    ? false, ffmpeg
   , enableGStreamer ? false, gst_all_1
  -, enableEigen ? false, eigen
  -, enableCuda ? false, cudatoolkit, gcc5
  +, enableEigen     ? false, eigen
  +, enableCuda      ? false, cudatoolkit, gcc5
   }:
   
   let
  -  version = "3.1.0";
  +  version = "3.2.0";
  +
  +  src = fetchFromGitHub {
  +    owner  = "opencv";
  +    repo   = "opencv";
  +    rev    = version;
  +    sha256 = "0f59g0dvhp5xg1xa3r4lp351a7x0k03i77ylgcf69ns3y47qd16p";
  +  };
   
     contribSrc = fetchFromGitHub {
  -    owner = "Itseez";
  -    repo = "opencv_contrib";
  -    rev = version;
  -    sha256 = "153yx62f34gl3zd6vgxv0fj3wccwmq78lnawlda1f6xhrclg9bax";
  +    owner  = "opencv";
  +    repo   = "opencv_contrib";
  +    rev    = version;
  +    sha256 = "1lynpbxz1jay3ya5y45zac5v8c6ifgk4ssn8d1chfdk3spi691jj";
  +  };
  +
  +  vggFiles = fetchFromGitHub {
  +    owner  = "opencv";
  +    repo   = "opencv_3rdparty";
  +    rev    = "fccf7cd6a4b12079f73bbfb21745f9babcd4eb1d";
  +    sha256 = "0r9fam8dplyqqsd3qgpnnfgf9l7lj44di19rxwbm8mxiw0rlcdvy";
  +  };
  +
  +  bootdescFiles = fetchFromGitHub {
  +    owner  = "opencv";
  +    repo   = "opencv_3rdparty";
  +    rev    = "34e4206aef44d50e6bbcd0ab06354b52e7466d26";
  +    sha256 = "13yig1xhvgghvxspxmdidss5lqiikpjr0ddm83jsi0k85j92sn62";
     };
   
     opencvFlag = name: enabled: "-DWITH_${name}=${if enabled then "ON" else "OFF"}";
  -
   in
   
   stdenv.mkDerivation rec {
     name = "opencv-${version}";
  -  inherit version;
  +  inherit version src;
   
  -  src = fetchFromGitHub {
  -    owner = "Itseez";
  -    repo = "opencv";
  -    rev = version;
  -    sha256 = "1l0w12czavgs0wzw1c594g358ilvfg2fn32cn8z7pv84zxj4g429";
  -  };
  +  postUnpack =
  +    (lib.optionalString enableContrib ''
  +      cp --no-preserve=mode -r "${contribSrc}/modules" "$NIX_BUILD_TOP/opencv_contrib"
   
  -  patches =
  -    lib.optionals enableCuda [
  -      (fetchpatch { # Patch for CUDA 8 compatibility
  -        url = "https://github.com/opencv/opencv/commit/10896129b39655e19e4e7c529153cb5c2191a1db.patch";
  -        sha256 = "0jka3kxxywgs3prqqgym5kav6p73rrblwj50k1nf3fvfpk194ah1";
  -      })
  -      (fetchpatch { # Patch to add CUDA Compute Capability compilation targets up to 6.0
  -        url = "https://github.com/opencv/opencv/commit/d76f258aebdf63f979a205cabe6d3e81700a7cd8.patch";
  -        sha256 = "00b3msfgrcw7laij6qafn4b18c1dl96xxpzwx05wxzrjldqb6kqg";
  -      })
  -    ]
  -    ++ lib.optional enablePython (fetchpatch { # Patch to fix FlannBasedMatcher under python
  -      url = "https://github.com/opencv/opencv/commit/05cfe28612fd8dc8fb0ccb876df945c7b435dd26.patch";
  -      sha256 = "0niza5lybr1ljzdkyiapr16laa468168qinpy5qn00yimnaygpm6";
  -    });
  +      for name in vgg_generated_48.i \
  +                  vgg_generated_64.i \
  +                  vgg_generated_80.i \
  +                  vgg_generated_120.i; do
  +        ln -s "${vggFiles}/$name" "$NIX_BUILD_TOP/opencv_contrib/xfeatures2d/src/$name"
  +      done
   
  +      for name in boostdesc_bgm.i          \
  +                  boostdesc_bgm_bi.i       \
  +                  boostdesc_bgm_hd.i       \
  +                  boostdesc_binboost_064.i \
  +                  boostdesc_binboost_128.i \
  +                  boostdesc_binboost_256.i \
  +                  boostdesc_lbgm.i; do
  +        ln -s "${bootdescFiles}/$name" "$NIX_BUILD_TOP/opencv_contrib/xfeatures2d/src/$name"
  +      done
  +    '');
     preConfigure =
  -    # By default ippicv gets downloaded by cmake each time opencv is build. See:
  -    # https://github.com/opencv/opencv/blob/3.1.0/3rdparty/ippicv/downloader.cmake
  -    # Fortunately cmake doesn't download ippicv if it's already there.
  -    # So to prevent repeated downloads we store it in the nix store
  -    # and create a symbolic link to it.
  -    let version  = "20151201";
  -        md5      = "808b791a6eac9ed78d32a7666804320e";
  -        sha256   = "1nph0w0pdcxwhdb5lxkb8whpwd9ylvwl97hn0k425amg80z86cs3";
  -        rev      = "81a676001ca8075ada498583e4166079e5744668";
  -        platform = if stdenv.system == "x86_64-linux" || stdenv.system == "i686-linux" then "linux"
  -                   else throw "ICV is not available for this platform (or not yet supported by this package)";
  -        name = "ippicv_${platform}_${version}.tgz";
  -        ippicv = fetchurl {
  -          url = "https://raw.githubusercontent.com/opencv/opencv_3rdparty/${rev}/ippicv/${name}";
  -          inherit sha256;
  -        };
  -        dir = "3rdparty/ippicv/downloads/${platform}-${md5}";
  -    in lib.optionalString enableIpp
  -      ''
  -        mkdir -p "${dir}"
  -        ln -s "${ippicv}" "${dir}/${name}"
  -      '';
  +    (let version  = "20151201";
  +         md5      = "808b791a6eac9ed78d32a7666804320e";
  +         sha256   = "1nph0w0pdcxwhdb5lxkb8whpwd9ylvwl97hn0k425amg80z86cs3";
  +         rev      = "81a676001ca8075ada498583e4166079e5744668";
  +         platform = if stdenv.system == "x86_64-linux" || stdenv.system == "i686-linux" then "linux"
  +                    else throw "ICV is not available for this platform (or not yet supported by this package)";
  +         name = "ippicv_${platform}_${version}.tgz";
  +         ippicv = fetchurl {
  +           url = "https://raw.githubusercontent.com/opencv/opencv_3rdparty/${rev}/ippicv/${name}";
  +           inherit sha256;
  +         };
  +         dir = "3rdparty/ippicv/downloads/${platform}-${md5}";
  +     in lib.optionalString enableIpp ''
  +          mkdir -p "${dir}"
  +          ln -s "${ippicv}" "${dir}/${name}"
  +        ''
  +    ) +
  +    (lib.optionalString enableContrib ''
  +      cmakeFlagsArray+=("-DOPENCV_EXTRA_MODULES_PATH=$NIX_BUILD_TOP/opencv_contrib")
  +    '');
   
     buildInputs =
          [ zlib ]
  
positive.code:     ++ lib.optional enableFfmpeg ffmpeg
      ++ lib.optionals enableGStreamer (with gst_all_1; [ gstreamer gst-plugins-base ])
      ++ lib.optional enableEigen eigen
      ++ lib.optional enableCuda [ cudatoolkit gcc5 ]
      ;
  
    propagatedBuildInputs = lib.optional enablePython pythonPackages.numpy;
  
negative.code:     (opencvFlag "OPENEXR" enableEXR)
      (opencvFlag "CUDA" enableCuda)
      (opencvFlag "CUBLAS" enableCuda)
    ] ++ lib.optionals enableCuda [ "-DCUDA_FAST_MATH=ON" ]
      ++ lib.optional enableContrib "-DBUILD_PROTOBUF=off";
  
    enableParallelBuilding = true;
  
  