anchor.diff:  # Switch back to dialog for any ad-hoc use of apt-get
   ENV DEBIAN_FRONTEND=dialog
   
  -# todo: perhaps this can be copied with a chown into dotfiles initially
  -COPY \
  +COPY --chown=$USR:$GRP \
       docker_prereqs/install_system.sh \
  -    docker_prereqs/system-requirements.txt \
  -    $HOMEDIR/docker_prereqs/
  +    $HOMEDIR/dotfiles/docker_prereqs/
   
  -RUN $HOMEDIR/docker_prereqs/install_system.sh \
  +RUN $HOMEDIR/dotfiles/docker_prereqs/install_system.sh \
       && rm -fr $HOMEDIR/docker_prereqs
   
   ENV LANG=en_US.UTF-8 \
  
positive.code: 
  USER $USR
  
  # todo: fix this so it doesn't bust docker cache as often
  COPY . $HOMEDIR/dotfiles
  
  RUN ["/bin/zsh", "-c", "$HOMEDIR/dotfiles/docker_prereqs/install_user.sh"]
  
  # todo: figure out a better entrypoint
  # ENTRYPOINT ["/usr/bin/zsh"]
  
negative.code:     # todo: check if needed: apt-utils dialog less iproute2 procps
      #
      # install system packages
      && apt-get -y install --no-install-recommends \
          `cat $HOMEDIR/dotfiles/docker_prereqs/system-requirements.txt` 2>&1 \
      #
      # Clean up
      && apt-get autoremove -y \
  