anchor.diff:  
   RUN chown root:root /usr/bin/sudo && chmod 4755 /usr/bin/sudo
   
  -# install ruby/rails/rvm
  -ADD ./files/etc/gemrc /etc/gemrc
  -RUN apt-get update \
  -    && apt-get install -y \
  -        gawk \
  -        libxml2-dev \
  -        libxslt-dev \
  -        libgdbm-dev \
  -        sqlite3 \
  -    && sudo -u ubuntu -i bash -l -c " \
  -        echo 'Installing rvm...' \
  -            && gpg -q --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 \
  -            && (curl -sSL https://get.rvm.io | sudo bash -s stable --autolibs=enabled) \
  -    " \
  -    && usermod -a -G rvm ubuntu \
  -    && sudo -u ubuntu -i bash -l -c " \
  -        echo 'Installing stable ruby version...' \
  -            && rvm install ruby-2.3.0 \
  -                && rvm use ruby-2.3.0 --default \
  -                && NOKOGIRI_USE_SYSTEM_LIBRARIES=1 gem install rails \
  -        && echo 'Installing additional ruby versions...' \
  -            && rvm install ruby-2.3.0 \
  -                && rvm use 2.3.0@rails5 --create \
  -                && NOKOGIRI_USE_SYSTEM_LIBRARIES=1 gem install rails -v 5.0.0.beta1 \
  -            && rvm install ruby-2.2.4 \
  -                && rvm use 2.2.4@rails4 -- create \
  -                && NOKOGIRI_USE_SYSTEM_LIBRARIES=1 gem install rails -v 4.2.5 \
  -            && rvm install ruby-1.9.3-p551 \
  -                && rvm use 1.9.3-p551@rails3.2 --create \
  -                && NOKOGIRI_USE_SYSTEM_LIBRARIES=1 gem install rails -v 3.2.22 \
  -    " \
  -    && /usr/local/rvm/bin/rvm cleanup all
  -    
   # 32-bit support
   RUN dpkg --add-architecture i386 && \
       apt-get update && \
  
positive.code:     libboost-all-dev libzmq-dev libwww-curl-perl libbz2-dev dpkg-dev \
      ruby1.9.1-dev dialog python-gtk2 libpango1.0 libpango1.0-dev \
      libmysqlclient-dev
  
  # Deployment
  # Can't include new npm since it makes "npm install -g npm" fail:
  
negative.code: # RUN apt-get install -y texlive-full
  
  # editors
  RUN apt-get install -y vim vim-addon-manager vim-vimoutliner vim-doc
  RUN apt-get install -y emacs ctags indent
  
  # X11
  