anchor.diff:  # install
   COPY . .
   RUN ./install.sh
  -
   RUN pip3 install --upgrade setuptools testresources 
   RUN pip3 install --upgrade -r requirements.txt
   RUN pip3 install --upgrade cmake
   
   # build and test
  -RUN mkdir -p build && \
  -    cd build && \
  -    cmake -DPython_TARGET_VERSION=${PYVERSION} -DCMAKE_CXX_COMPILER=`which clang++` ../open_spiel && \
  -    make -j4 && \
  -    ctest -j4
  -COPY . build
  +RUN mkdir -p build
  +WORKDIR /repo/build
  +RUN cmake -DPython_TARGET_VERSION=${PYVERSION} -DCMAKE_CXX_COMPILER=`which clang++` ../open_spiel 
  +RUN make -j12
  +RUN ctest -j12
  +ENV PYTHONPATH=${PYTHONPATH}:/repo
  +ENV PYTHONPATH=${PYTHONPATH}:/repo/build/python
  +WORKDIR /repo/open_spiel
   
  -ENV PYTHONPATH=${PYTHONPATH}:/
  -ENV PYTHONPATH=${PYTHONPATH}:/build/python
  -
  -WORKDIR ./open_spiel
  +# minimal image for development in Python
  +FROM python:3.6-slim-buster as python-slim
  +RUN mkdir repo
  +WORKDIR /repo
  +COPY --from=base /repo .
  +RUN pip3 install --upgrade -r requirements.txt
  +RUN pip3 install matplotlib
  +ENV PYTHONPATH=${PYTHONPATH}:/repo
  +ENV PYTHONPATH=${PYTHONPATH}:/repo/build/python
  +WORKDIR /repo/open_spiel
  
positive.code: FROM ubuntu:18.04
  RUN apt update
  RUN dpkg --add-architecture i386 && apt update
  RUN apt-get -y install \
  
negative.code:     python3-setuptools \
      python3-wheel \
      sudo
  RUN mkdir repo
  WORKDIR /repo
  
  RUN sudo pip3 install --upgrade pip
  RUN sudo pip3 install matplotlib
  