anchor.diff:  MAINTAINER qqbuby <qqbuby@gmail.com>
   
   ENV RTD_COMMIT ed4f90e4
  +ENV PYTHON_PIP_VERSION 9.0.1
  +ENV PIP_TIMEOUT 60
  +#ENV PIP_INDEX_URL https://mirrors.ustc.edu.cn/pypi/web/simple
   
  -ENV PYTHON_PIP_VERSION 9.0.1
  -ENV PIP_DEFAULT_TIMEOUT 60
  -# ENV PIP_INDEX_URL https://mirrors.ustc.edu.cn/pypi/web/simple
  -
  -# RUN mv /etc/apt/sources.list /etc/apt/sources.list.bak \
  -#     && echo 'deb http://mirrors.163.com/debian stable main contrib non-free' > /etc/apt/sources.list
  +#RUN mv /etc/apt/sources.list /etc/apt/sources.list.bak \
  +#    && echo 'deb http://mirrors.163.com/debian stable main contrib non-free' > /etc/apt/sources.list
   
   RUN DEBIAN_FRONTEND=noninteractive apt-get update \
       && DEBIAN_FRONTEND=noninteractive apt-get install -y \
  
positive.code:     libxml2-dev \
      libxslt1-dev \
      zlib1g-dev \
      git \
      && DEBIAN_FRONTEND=noninteractive apt-get -y autoremove
  
  RUN pip install --upgrade --force-reinstall "pip==$PYTHON_PIP_VERSION" \
      && rm -rf ~/.cache
  
  RUN pip --no-cache-dir install virtualenv
  
negative.code: RUN mkdir /var/readthedocs/checkouts
  WORKDIR /var/readthedocs/checkouts
  
  RUN curl -ksSL https://github.com/rtfd/readthedocs.org/archive/$RTD_COMMIT.tar.gz | tar xz \
      && mv readthedocs.org-${RTD_COMMIT}* readthedocs
  WORKDIR /var/readthedocs/checkouts/readthedocs
  
  # Install the depedencies using pip (included inside of virtualenv)
  RUN . /var/readthedocs/bin/activate \
  