anchor.diff:          echo "Acquire::http::Proxy \"${APT_CACHER}\";" | tee /etc/apt/apt.conf.d/01proxy ; \
       fi; \
       apt-get -qq update && \
  -    apt-get -qy install --no-install-recommends \
  +    apt-get -qy install --no-install-recommends --allow-unauthenticated \
           # for deployment
           openssh-client \
           rsync \
  
positive.code:         # required for PDF meta analysis
          poppler-utils \
          zlibc \
      # clean up
      && apt-get clean && \
      rm -rf /var/lib/apt/lists/* /etc/apt/apt.conf.d/01proxy
  
negative.code: ADD requirements.txt ./
  RUN pip3 --no-cache-dir install --find-links file://${PWD}/cache -r requirements.txt
  
  #
  # Mermaid
  #
  RUN yarn add mermaid.cli
  
  VOLUME /pandoc
  WORKDIR /pandoc
  ADD pandoc.sh /usr/local/bin
  