anchor.diff:  ENV CPPFLAGS -I${MKLROOT}/include
   
   RUN wget -nv https://www.mpich.org/static/downloads/3.3/mpich-3.3.tar.gz \
  -    && tar xvzf mpich-3.3.tar.gz \
  +    && tar xzf mpich-3.3.tar.gz \
       && cd mpich-3.3 \
       && ./configure \
       && make -j4 \
  
positive.code:     conda config --add channels intel && \
      conda config --set always_yes yes && \
      conda update conda && \
      conda install python=3.7 pip numpy scipy && \
      conda clean -a -y
  
  # ugly: Tractor's mp_fourier module detects the $CC='icc' exactly
  
negative.code:     && cd .. && rm -Rf mpich-3.3
  # defaults to installing in /usr/local
  
  RUN pip --no-cache-dir install cython
  
  # mpi4py / mpicc can't handle -ax=knl or -x=haswell (it compiles using gcc?)
  ENV CFLAGS -O3 -g -fPIC -std=gnu99 -pthread
  RUN git clone https://github.com/mpi4py/mpi4py.git \
           && (cd mpi4py \
           && python setup.py build \
           && python setup.py install) \
           && rm -Rf mpi4py
  ENV CFLAGS -O3 -g -fPIC -std=gnu99 -pthread -x=haswell
  
  RUN git clone https://github.com/astromatic/sextractor.git sourceextractor \
      && cd sourceextractor \
  