anchor.diff:  USER builder
   WORKDIR /home/builder/src
   
  +ARG rust_version=1.41.0
  +
   RUN wget -O $HOME/rustup.sh --secure-protocol=TLSv1_2 https://sh.rustup.rs \
       && chmod +x $HOME/rustup.sh \
       && $HOME/rustup.sh -y \
  
positive.code:     && apt-get update \
      && apt-get upgrade --assume-yes
  
  ARG rust_version=1.41.0
  ARG cxx_package
  ARG cc
  ARG cxx
  
  RUN apt-get update \
      && apt-get install --assume-yes --no-install-recommends \
  
negative.code:     && chmod a+w $HOME/.cargo
  
  ENV HOME /home/builder
  
  ARG cc
  ARG cxx
  
  ENV CC=$cc
  ENV CXX=$cxx
  