anchor.diff:  # Install `pip` packages. #
   ###########################
   
  -RUN virtualenv "$VIRTUAL_ENV"
  +RUN python3 -m venv "$VIRTUAL_ENV"
   ENV PATH="$VIRTUAL_ENV/bin:$PATH"
   RUN pip install  --quiet --upgrade pip && \
       pip install  --quiet pip-tools
  
positive.code:         libproj-dev \
          locales \
          postgresql-client \
          python3-virtualenv \
          rsync \
          runit-init \
          vim \
          wait-for-it && \
      apt-get clean && \
          rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
negative.code: FROM python:3.8
  
  ENV DEBIAN_FRONTEND=noninteractive
  ENV LANG=en_US.UTF-8
  