anchor.diff:  # This has no AVX1, AVX2, or PCLMUL, but it does have SSE4.2.
   # UCSC has a Nehalem machine that we want to support.
   RUN sed -i s/march=native/march=nehalem/ deps/sdsl-lite/CMakeLists.txt
  -RUN make get-deps && . ./source_me.sh && env && make include/vg_git_version.hpp && CXXFLAGS=" -march=nehalem " make -j8 && make static && strip bin/vg
  +RUN make get-deps && . ./source_me.sh && env && make include/vg_git_version.hpp && CXXFLAGS=" -march=nehalem " make -j ${THREADS} && make static && strip bin/vg
   
   ENV PATH /vg/bin:$PATH
   
   ############################################################################################
   FROM build AS test
  +ARG THREADS=8
   
   RUN echo test > /stage.txt
   
  
positive.code: WORKDIR /vg
  
  FROM base AS build
  
  RUN echo build > /stage.txt
  
  
negative.code: 
  # Fail if any non-portable instructions were used
  RUN /bin/bash -e -c 'if objdump -d /vg/bin/vg | grep vperm2i128 ; then exit 1 ; else exit 0 ; fi'
  # Set the default number of threads to the number we are supposed to use.
  ENV OMP_NUM_THREADS ${THREADS}
  # Run tests in the middle so the final container that gets tagged is the run container.
  RUN make test
  
  