anchor.diff:  RUN ln -s /usr/bin/python3 /usr/bin/python
   
   # unwise_psf
  -RUN cd /src \
  -    && git clone https://github.com/legacysurvey/unwise_psf.git \
  +RUN git clone https://github.com/legacysurvey/unwise_psf.git \
       && cd unwise_psf && git checkout dr8
   
   # Legacypipe
  -RUN cd /src \
  -    && git clone http://github.com/legacysurvey/legacypipe.git legacypipe
  +RUN git clone http://github.com/legacysurvey/legacypipe.git legacypipe
   
   ENV PYTHONPATH /usr/local/lib/python:/src/unwise_psf/py:/src/legacypipe/py
   ENV WISE_PSF_DIR /src/unwise_psf/etc
  
positive.code: 
  ######## Stage 2 ########
  FROM registry.services.nersc.gov/nersc/intel_cxx_fort_mpi_mkl_runtime
  COPY --from=builder /usr/local /usr/local
  
  ENV PYTHON python3
  ENV PYTHON_CONFIG python3-config
  
negative.code: ENV PYTHON_CONFIG python3-config
  ENV PYTHON_SCRIPT "/usr/bin/env python3"
  
  RUN mkdir -p /src
  WORKDIR /src
  
  # Astrometry.net
  RUN git clone http://github.com/dstndstn/astrometry.net.git astrometry \
      && cd astrometry \
      && make -j4 && make \
      && make py \
  