anchor.diff:  
   # Install system requirements
   RUN apt-get update && \
  -    apt-get install -y software-properties-common && \
  -    apt-add-repository -y ppa:deadsnakes/ppa && apt-get update && \
       # Global requirements
       DEBIAN_FRONTEND=noninteractive apt-get install --yes \
       build-essential \
  
positive.code:     libxml2-dev \
      libxmlsec1-dev \
      libxslt1-dev \
      swig \
      # openedx requirements
      gettext \
  
negative.code:     libxslt1-dev \
      ntp \
      pkg-config \
      python3-dev \
      python3-pip \
      python3.5 \
      && rm -rf /var/lib/apt/lists/*
  
  RUN locale-gen en_US.UTF-8
  ENV LANG en_US.UTF-8
  ENV LANGUAGE en_US:en
  ENV LC_ALL en_US.UTF-8
  
  RUN ln -s /usr/bin/pip3 /usr/bin/pip
  RUN ln -s /usr/bin/python3 /usr/bin/python
  
  WORKDIR /edx/app/edxapp/edx-platform
  
  