anchor.diff:      && apk add --virtual .postgis-run-deps-testing \
           --repository http://dl-cdn.alpinelinux.org/alpine/edge/testing \
           geos \
  -        gdal \
  -        proj4 \
  +        gdal-dev \
  +        proj4-dev \
           protobuf-c \
       && apk add --virtual .postgis-run-deps \
           json-c \
  
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: ARG POSTGIS_SOURCE="https://download.osgeo.org/postgis/source/postgis-$POSTGIS_VERSION.tar.gz"
  
  ### Checksums
  ARG CGAL_SHA256="3956225817967e047aa099e06e73e1d3c2fe8aae1ae5b672e470fb34c589c32f"
  #ARG POSTGIS_SHA256="b9754c7b9cbc30190177ec34b570717b2b9b88ed271d18e3af68eca3632d1d95"
  
  ### update apk and existing packages
  