anchor.diff:    bash \
     build-essential \
     bzip2 \
  +  ca-certificates \
     curl \
     file \
     git \
  
positive.code:   git checkout v1.6.0 && \
    python ./configure.py --bootstrap && \
    ./ninja && \
    cp ./ninja /usr/bin/
  
negative.code:   tar \
    vim \
    wget \
    xz-utils && \
    apt-get -y clean
  
  # Build and install CMake from source.
  WORKDIR /usr/src
  RUN git clone git://cmake.org/cmake.git CMake && \
    cd CMake && \
    git checkout v3.4.3 && \
    cd .. && mkdir CMake-build && \
    /usr/src/CMake/bootstrap \
      --parallel=$(nproc) \
      --prefix=/usr && \
    make -j$(nproc) && \
    ./bin/cmake -DCMAKE_USE_SYSTEM_CURL:BOOL=ON \
      -DCMAKE_BUILD_TYPE:STRING=Release \
      -DCMAKE_USE_OPENSSL:BOOL=ON . && \
    make install && \
    cd .. && \
    rm -rf CMake*
  
  # Build and install Ninja from source
  RUN git clone https://github.com/martine/ninja.git && \
  