anchor.diff:      pandoc \
       tar \
       wget ; \
  -    apt clean ; \
  -    npm install cssjanus
  +    rm -rf /var/lib/apt/lists/*; \
  +    /usr/bin/npm install cssjanus
   
   # Utility scripts that run in the virtual environment.
   COPY bin /app/bin/
  
positive.code: COPY requirements /requirements
  
  # Build dependencies.
  RUN apt install -y \
      build-essential \
      gcc \
      libffi-dev \
      libjpeg62-turbo-dev \
      libxml2-dev \
      musl-dev \
      python3-dev \
      zlib1g-dev ; \
      virtualenv /venv ; \
      . /venv/bin/activate ; \
      pip3 install -r /requirements/wmf.txt
  
negative.code: # CSS Janus is the thing actually used to generate the rtl css.
  # Pandoc is used for rendering wikicode resource descriptions
  # into html for display. We do need this on the live image.
  RUN apt update ; \
      apt install -y --no-install-recommends \
      bash \
      gettext \
      git \
  