anchor.diff:  ENV DOCKERFILE_BASE=$BASE                     \
       DOCKERFILE_DISTRO=$DISTRO                 \
       DOCKERFILE_DISTRO_VERSION=$DISTRO_VERSION \
  -    SPACK_ROOT=/spack                         \
  +    SPACK_ROOT=/opt/spack                     \
       FORCE_UNSAFE_CONFIGURE=1                  \
       DEBIAN_FRONTEND=noninteractive            \
       CURRENTLY_BUILDING_DOCKER_IMAGE=1         \
  
positive.code: 
  MASK POP
  
  RUN rm -rf $SPACK_ROOT/.git                                          \
   && pip install boto3                                                \
   && (  echo ". /usr/share/lmod/lmod/init/bash"                       \
      && echo ". $SPACK_ROOT/share/spack/setup-env.sh"                 \
      && echo "if [ \"\$CURRENTLY_BUILDING_DOCKER_IMAGE\" '!=' '1' ]"  \
      && echo "then"                                                   \
      && echo "  . $SPACK_ROOT/share/spack/spack-completion.bash"      \
      && echo "fi"                                                   ) \
          >> /etc/profile.d/spack.sh                                   \
   && ln -s $SPACK_ROOT/share/spack/docker/handle-ssh.sh               \
          /etc/profile.d/handle-ssh.sh                                 \
   && ln -s $SPACK_ROOT/share/spack/docker/handle-prompt.sh            \
          /etc/profile.d/handle-prompt.sh                              \
   && mkdir -p /root/.spack                                            \
   && cp $SPACK_ROOT/share/spack/docker/modules.yaml                   \
          /root/.spack/modules.yaml                                    \
   && rm -rf /root/*.*
  
  MASK PUSH
  
negative.code: 
  WORKDIR /root
  SHELL ["/bin/bash", "-l", "-c"]
  
  # TODO: add a command to Spack that (re)creates the package cache
  RUN spack spec hdf5+mpi
  
  ENTRYPOINT ["/bin/bash", "/opt/spack/share/spack/docker/entrypoint.bash"]
  CMD ["docker-shell"]
  
  