anchor.diff:  COPY --from=docs/docker.github.io:v18.03 ${TARGET} /
   COPY --from=docs/docker.github.io:v18.09 ${TARGET} /
   
  +# Stage either with, or without archives, depending on ENABLE_ARCHIVES
  +FROM archives-${ENABLE_ARCHIVES} AS archives
   
   # Fetch upstream resources (reference documentation)
   # Only add the files that are needed to build these reference docs, so that
  
positive.code: CMD echo -e "Docker docs are viewable at:\nhttp://0.0.0.0:4000"; exec nginx -g 'daemon off;'
  
  
  # Stage with static HTML for all archives
  FROM scratch AS archives
  ENV TARGET=/usr/share/nginx/html
  # To add a new archive, add it here and ALSO edit _data/docsarchive/archives.yaml
  # to add it to the drop-down
  
negative.code: RUN find ${TARGET} -type f -name '*.html' | grep -vE "v[0-9]+\." | while read i; do sed -i 's#href="https://docs.docker.com/#href="/#g' "$i"; done
  
  
  # Final stage, which includes nginx, and, depending on ENABLE_ARCHIVES, either
  # current docs and archived versions (ENABLE_ARCHIVES=true), or only the current
  # docs (ENABLE_ARCHIVES=false).
  #
  # To build current docs, including archives:
  # DOCKER_BUILDKIT=1 docker build -t docs .
  #
  # To build without archives:
  # DOCKER_BUILDKIT=1 docker build -t docs --build-arg ENABLE_ARCHIVES=false .
  FROM deploybase AS deploy
  COPY --from=archives / ${TARGET}
  COPY --from=current  ${TARGET} ${TARGET}
  