anchor.diff:  
   # Install packages for building ruby
   RUN apt-get update && apt-get upgrade -y
  -RUN apt-get install -y --force-yes build-essential curl git zlib1g-dev libssl-dev libreadline-dev libyaml-dev libxml2-dev libxslt-dev
  +RUN apt-get install -y --force-yes autoconf bison build-essential g++ libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm5 libgdbm-dev
   RUN apt-get clean
   
   # Install rbenv, ruby-build and rbenv-default-gems
  
positive.code: # config
  ENV PATH /usr/local/rbenv/bin:$PATH
  ENV RBENV_ROOT /usr/local/rbenv
  ENV CONFIGURE_OPTS --disable-install-doc --with-arch=i686 --enable-shared
  
  RUN echo 'eval "$(rbenv init -)"' >> /etc/profile.d/rbenv.sh # or /etc/profile
  RUN echo 'eval "$(rbenv init -)"' >> /root/.bashrc
  
negative.code: ADD ./gems.txt /usr/local/rbenv/default-gems
  ADD ./build_packages.sh /root/build_packages.sh
  
  # build
  RUN /usr/local/rbenv/plugins/ruby-build/install.sh
  RUN rbenv update
  RUN xargs -L 1 rbenv install < /root/versions.txt
  RUN rbenv global $(head -n 1 /root/versions.txt)
  
  # create package
  RUN rbenv exec gem install fpm
  CMD sh /root/build_packages.sh
  