anchor.diff:  USER developer
   
   # Add `/home/developer/.gem_local` for sudo-less global gem installs. Note:
  -# this will be wiped once the container quits.
  +# this will be wiped once the container quits, except in this file.
   RUN mkdir ~/.gem_local && echo 'export GEM_HOME="$HOME/.gem_local"' >> ~/.bashrc
   RUN echo 'export PATH="$HOME/bin:$HOME/.gem_local/bin:$PATH"' >> ~/.bashrc
   
  
positive.code: RUN echo "gem: --no-ri --no-rdoc" > ~/.gemrc
  
  # Add bundler config to use `/data/vendor/bundle` as the gem install path
  RUN mkdir ~/.bundle && echo -e "BUNDLE_DISABLE_LOCAL_BRANCH_CHECK: 'true'\nBUNDLE_PATH: vendor/bundle\nBUNDLE_DISABLE_SHARED_GEMS: 'true'\n" > ~/.bundle/config
  
  RUN /bin/bash -lc "gem install bundler"
  
  
negative.code: MAINTAINER alex@alexblackie.com
  
  ##
  # Install tools and dependencies
  ##
  RUN dnf install -y tar gcc make binutils glibc-devel patch \
  	zlib-devel libyaml-devel openssl-devel gdbm-devel readline-devel ncurses-devel libffi-devel curl-devel \
  	nodejs libxslt-devel libxml2-devel postgresql-devel sqlite-devel mariadb-devel git file fontconfig bzip2 ImageMagick && \
  	dnf clean all
  
  ##
  # Install a Ruby by compiling from source
  ##
  
  RUN curl -Lo /tmp/ruby.tar.gz https://cache.ruby-lang.org/pub/ruby/2.3/ruby-2.3.1.tar.gz
  RUN tar -zxf /tmp/ruby.tar.gz -C /tmp/ && cd /tmp/ruby-2.3.1 && \
  	./configure && make && make install && \
  	rm -rf /tmp/ruby-2.3.1 /tmp/ruby.tar.gz
  
  ##
  # Install PhantomJS for feature test suites
  ##
  RUN curl -Lo /tmp/phantomjs.tar.bz2 https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2 && \
  	tar -xjf /tmp/phantomjs.tar.bz2 -C /tmp && \
  	mv /tmp/phantomjs-2.1.1-linux-x86_64/bin/phantomjs /usr/local/bin/phantomjs && \
  	rm -fr /tmp/phantomjs.tar.bz2 /tmp/phantomjs-2.1.1-linux-x86_64
  
  ##
  # Set up development environment configuration
  