anchor.diff:    ghostscript ImageMagick
   
   # Install system-indepedent python environment
  -RUN virtualenv /opt/python && \
  +RUN pyvenv-3.4 --without-pip /opt/python && \
  +  cd /tmp && \
  +  curl -L -s https://bootstrap.pypa.io/get-pip.py | /opt/python/bin/python && \
     mkdir -p /opt/ipython
   
   # Install from PIP
  
positive.code: COPY opt /opt
  COPY var /var
  
  # Because COPY doesn't respoect USER...
  USER root
  RUN chown -R researcher:researcher /etc /opt /var
  USER researcher
  
negative.code: # - Useful IPython libraries
  # - SciPy & netCDF4 (which expect numpy to be installed first)
  RUN source /opt/python/bin/activate && \
    pip install --upgrade pip wheel && \
    pip install \
      tornado pyzmq jinja2 \
      ipython \
      jsonschema \
      ipythonblocks numpy pandas matplotlib gitpython && \
    pip install scipy netCDF4 && \
    rm -rf /home/researcher/.cache
  