anchor.diff:                  python3-skimage \
                   python3-pylibmc \
                   python3-pil \
  -                libpq5 \
  -                webp \
  +                libwebp5 \
  +                libpng3 \
  +                libjpeg62 \
  +                libtiff5 \
                   imagemagick \
                   cython3 \
                   gdal-bin \
  
positive.code:                 libboost-system-dev \
                  libboost-thread-dev \
                  libz-dev \
                  libharfbuzz-dev \
                  libwebp-dev \
                  liblcms2-dev  \
                  libjpeg-dev \
                  libtiff-dev \
                  libproj-dev \
                  libgeos-dev \
                  libgdal-dev \
                  libicu-dev \
                  libfreetype6-dev \
                  libsqlite3-dev \
                  libpq-dev \
  
negative.code:                 python3-gdal
  
  #
  # Build python-mapnik form source, since Mapnik's pip package only supports python2,
  # and their official PPA is broken.  Hopefully this will be fixed in ubuntu-16.04
  #
  # WARNING: Very slow!!!, and memory hungry using GCC:
  #   - 1~2 cores: 8GB
  #   - 4~8 cores: 16GB
  #   - >=16 cores: 32GB
  #
  # Requires freetype2.6 otherwise Google Noto CJK fonts don't get auto hinting.
  
  WORKDIR     /tmp
  
  ENV         FREETYPE_VERSION=VER-2-6-1 \
              MAPNIK_VERSION=v3.0.8
  
  # Fixes https://github.com/mapnik/mapnik/issues/3090
  COPY        3090-fix.diff ./
  
  RUN         set -x \
              && DEV_PACKAGES="python3-cairo-dev \
  