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