anchor.diff:  RUN dpkg-reconfigure locales
   
   # Python binary dependencies, developer tools
  -RUN apt-get update && apt-get install -y -q \
  +RUN apt-get install -y -q \
       build-essential \
       make \
       gcc \
  
positive.code: 
  # Not essential, but wise to set the lang
  # Note: Users with other languages should set this in their derivative image
  RUN apt-get update && apt-get install -y language-pack-en && \
      apt-get clean
  ENV LANGUAGE en_GB.UTF-8
  ENV LANG en_GB.UTF-8
  ENV LC_ALL en_GB.UTF-8
  
negative.code: # install jupyterhub
  ADD requirements.txt /tmp/requirements.txt
  RUN pip3 install -r /tmp/requirements.txt
  WORKDIR /srv/
  RUN git clone https://github.com/edinburghlivinglab/jupyterhub.git
  WORKDIR /srv/jupyterhub/
  RUN pip3 install .
  
  WORKDIR /srv/jupyterhub/
  