anchor.diff:  # RUN echo ls /code; ls /code
   # RUN cd /code; tox -r
   
  -# TODO consolidate all apt-get; clean up after install
  -RUN apt-get install -y xvfb
  +
  +ENV NODE_ARCHIVE ""
  +ENV NODE_DIR ""
   
   ENTRYPOINT ["purkinje", "-c", "purkinje.yml"]
  
positive.code: RUN echo 'Running installation'
  WORKDIR /code
  
  ENV NODE_DIR=node-v6.2.0-linux-x64
  ENV NODE_ARCHIVE=$NODE_DIR.tar.xz
  ENV PATH=/opt/node/bin:$PATH
  
  RUN apt-get -y update && apt-get install -y \
      firefox \
      gcc \
      libyaml-dev \
      make \
      python \
      python-dev \
      software-properties-common \
      wget \
      xz-utils
  
  # Install Google Chrome
  RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -
  
negative.code: WORKDIR /code
  RUN node --version
  RUN npm --version
  RUN python2.7 --version
  RUN ln -sf /usr/bin/python2.7 /usr/bin/python
  
  # Ubuntu's python-pip throws exception with requests lib
  # see https://bugs.launchpad.net/ubuntu/+source/python-pip/+bug/1306991
  