anchor.diff:  ENV RUBY_CC_VERSION 2.4.0:2.3.0:2.2.2:2.1.5:2.0.0
   
   RUN apt-get install -y g++-multilib
  +RUN apt-get install -y libssl-dev
   
   CMD bash
  
positive.code: # Install wrappers for strip commands as a workaround for "Protocol error" in boot2docker.
  RUN cp /tmp/build/strip_wrapper /root/
  RUN sudo chmod +rx /root/strip_wrapper
  RUN mv /opt/mingw/mingw32/bin/i686-w64-mingw32-strip /opt/mingw/mingw32/bin/i686-w64-mingw32-strip.bin && \
      mv /opt/mingw/mingw64/bin/x86_64-w64-mingw32-strip /opt/mingw/mingw64/bin/x86_64-w64-mingw32-strip.bin && \
      mv /usr/bin/i686-w64-mingw32-strip /usr/bin/i686-w64-mingw32-strip.bin && \
      mv /usr/bin/x86_64-w64-mingw32-strip /usr/bin/x86_64-w64-mingw32-strip.bin && \
      ln /root/strip_wrapper /opt/mingw/mingw32/bin/i686-w64-mingw32-strip && \
      ln /root/strip_wrapper /opt/mingw/mingw64/bin/x86_64-w64-mingw32-strip && \
      ln /root/strip_wrapper /usr/bin/i686-w64-mingw32-strip && \
      ln /root/strip_wrapper /usr/bin/x86_64-w64-mingw32-strip
  
  
negative.code: FROM ubuntu:17.04
  
  RUN apt-get -y update && \
      apt-get install -y curl git-core xz-utils build-essential wget unzip sudo gpg dirmngr
  
  # Add "rvm" as system group, to avoid conflicts with host GIDs typically starting with 1000
  RUN groupadd -r rvm && useradd -r -g rvm -G sudo -p "" --create-home rvm && \
      echo "source /etc/profile.d/rvm.sh" >> /etc/rubybashrc
  
  USER root
  RUN apt-get -y update && \
      apt-get install -y gcc-mingw-w64-x86-64 gcc-mingw-w64-i686 g++-mingw-w64-x86-64 g++-mingw-w64-i686 \
          gcc-multilib moreutils
  USER rvm
  
  # install rvm, RVM 1.26.0+ has signed releases, source rvm for usage outside of package scripts
  