anchor.diff:  
   FROM python:3.9-alpine
   
  -RUN apk add --update \
  +RUN echo '@edge-community https://dl-cdn.alpinelinux.org/alpine/edge/community' >> /etc/apk/repositories \
  +        && \
  +    apk add --update \
           bash \
           diffutils \
           g++ \
  
positive.code: 
  USER root
  RUN apk upgrade --update
  # Enable testing repository for nothing but package "supercronic".
  # It's done down here so that we get as little as possible from testing.
  RUN echo http://dl-cdn.alpinelinux.org/alpine/edge/testing >> /etc/apk/repositories \
          && \
      apk add --update supercronic
  USER wnpp-debian-net
  
negative.code:         musl-dev \
          postgresql-client \
          postgresql-dev \
          shadow \
          supercronic@edge-community
  
  RUN useradd --create-home --uid 1001 --non-unique wnpp-debian-net
  USER wnpp-debian-net
  