anchor.diff:  ARG POSTGIS_SOURCE="https://download.osgeo.org/postgis/source/postgis-$POSTGIS_VERSION.tar.gz"
   
   ### Checksums
  -ARG CGAL_SHA256="3e3dd7a64febda58be54c3cbeba329ab6a73b72d4d7647ba4931ecd1fad0e3bc"
  +ARG CGAL_SHA256="3956225817967e047aa099e06e73e1d3c2fe8aae1ae5b672e470fb34c589c32f"
   #ARG POSTGIS_SHA256="b9754c7b9cbc30190177ec34b570717b2b9b88ed271d18e3af68eca3632d1d95"
   
   ### update apk and existing packages
  
positive.code:     ### build packages from testing repo
      && apk add --virtual .build-deps-testing \
          --repository http://dl-cdn.alpinelinux.org/alpine/edge/testing \
          gdal-dev \
          geos-dev \
          proj4-dev \
          protobuf-c-dev \
      ### various runtime packages 
      && apk add --virtual .postgis-run-deps-edge \
  
negative.code: FROM postgres:11.3-alpine
  
  ### Versions
  ARG CGAL_VERSION="4.13.1"
  ARG SFCGAL_VERSION="1.3.6"
  ARG POSTGIS_VERSION="2.5.2"
  
  ### Download Locations
  ARG CGAL_SOURCE="https://github.com/CGAL/cgal/releases/download/releases%2FCGAL-$CGAL_VERSION/CGAL-$CGAL_VERSION.tar.xz"
  