anchor.diff:  ARG mainUser=sirfuser
   ARG UID=1000
   ARG GROUPS=1000
  -RUN addgroup --system --gid $GROUPS $mainUser
  -RUN adduser --home /home/$mainUser --shell /bin/bash --system --ingroup $mainUser --uid $UID $mainUser
  +RUN addgroup --system --gid "$GROUPS" "$mainUser"
  +RUN adduser --home /home/"$mainUser" --shell /bin/bash --system --ingroup "$mainUser" --uid "$UID" "$mainUser"
   #RUN echo "$mainUser:x:${uid}:${gid}:$mainUser,,,:/home/$mainUser:/bin/bash" >> /etc/passwd
   
  -RUN echo "$mainUser ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/$mainUser
  +RUN echo "$mainUser ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/"$mainUser"
   
  -USER $mainUser
  -ENV HOME /home/$mainUser
  +USER "$mainUser"
  +ENV HOME /home/"$mainUser"
   WORKDIR $HOME
   
   # Python (virtualenv)
  -ADD user_python-ubuntu.sh .
  +COPY user_python-ubuntu.sh .
   RUN bash user_python-ubuntu.sh
   RUN rm user_python-ubuntu.sh
   
  -ADD .bashrc .
  -ADD .profile .
  -RUN sudo chown $mainUser .bashrc .profile
  -RUN sudo chgrp $mainUser .bashrc .profile
  +COPY .bashrc .
  +COPY .profile .
  +RUN sudo chown "$mainUser" .bashrc .profile
  +RUN sudo chgrp "$mainUser" .bashrc .profile
   RUN sudo chmod 644 .bashrc .profile
   
   # SIRF
  -ADD user_sirf-ubuntu.sh .
  +COPY user_sirf-ubuntu.sh .
   RUN EXTRA_BUILD_FLAGS="-DCMAKE_BUILD_TYPE=Release -DUSE_SYSTEM_Boost=ON \
     -DUSE_SYSTEM_SWIG=ON -DUSE_SYSTEM_HDF5=ON -DUSE_SYSTEM_FFTW3=ON \
     -DUSE_SYSTEM_Armadillo=ON -DBUILD_STIR_EXECUTABLES=ON \
  
positive.code: 
  ENV DEBIAN_FRONTEND noninteractive
  
  RUN apt-get update && apt-get upgrade -y --no-install-recommends
  
  # Set locale, suppress warnings
  RUN apt-get update && apt-get install -y apt-utils locales
  RUN locale-gen en_GB.UTF-8
  
negative.code: ENV LANGUAGE en_GB:en
  #RUN localectl set-locale LANG="en_GB.UTF-8"
  
  COPY build_essential-ubuntu.sh .
  RUN bash build_essential-ubuntu.sh
  RUN rm build_essential-ubuntu.sh
  
  # Python (build)
  COPY build_python-ubuntu.sh .
  RUN bash build_python-ubuntu.sh
  RUN rm build_python-ubuntu.sh
  
  # Gadgetron
  COPY build_gadgetron-ubuntu.sh .
  RUN bash build_gadgetron-ubuntu.sh
  RUN rm build_gadgetron-ubuntu.sh
  
  # SIRF external deps
  COPY build_system-ubuntu.sh .
  RUN bash build_system-ubuntu.sh
  RUN rm build_system-ubuntu.sh
  
  