anchor.diff:  # gcc
   RUN add-apt-repository -y ppa:ubuntu-toolchain-r/test && \
       apt-get update && \
  -    apt-get install -y g++-8 gcc-8
  +    apt-get install -y g++-8 gcc-8 && \
  +    apt-get clean && \
  +    rm -rf /var/lib/apt/lists/*
   RUN update-alternatives --install /usr/bin/gcc  gcc  /usr/bin/gcc-8  1000 && \
       update-alternatives --install /usr/bin/g++  g++  /usr/bin/g++-8  1000 && \
       update-alternatives --install /usr/bin/gcov gcov /usr/bin/gcov-8 1000 && \
  
positive.code: RUN wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add - && \
      apt-add-repository "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-7 main" && \
      apt-get update && \
      apt-get install -y clang-7
  RUN update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-7 1000 && \
      update-alternatives --install /usr/bin/clang clang /usr/bin/clang-7 1000 && \
      update-alternatives --config clang && \
      update-alternatives --config clang++
  
  RUN apt-get clean
  
  RUN mkdir /iutest
  VOLUME [ "/iutest" ]
  WORKDIR /iutest
  
negative.code: LABEL maintainer "srz_zumix <https://github.com/srz-zumix>"
  
  RUN apt-get update -q -y && \
      apt-get install -y software-properties-common && \
      apt-get update -q -y && \
      apt-get install -y \
          wget vim iputils-ping sudo curl \
          libsqlite3-dev libssl-dev \
          python2.7 python2.7-dev python-virtualenv \
          git subversion \
          build-essential gdb && \
      apt-get clean && \
      rm -rf /var/lib/apt/lists/*
  
  # pyenv
  ENV PYENV_ROOT $HOME/.pyenv
  ENV PATH $HOME/.pyenv/shims:$HOME/.pyenv/bin:$PATH
  RUN wget https://raw.githubusercontent.com/yyuu/pyenv-installer/master/bin/pyenv-installer -O - | bash
  RUN pyenv --version && \
      pyenv install 2.7.13 && \
      pyenv install 3.5.2 && \
      pyenv install 3.6.0
  RUN pyenv local 2.7.13 && \
       pip install --upgrade setuptools pip tox requests && \
       pyenv local --unset
  