anchor.diff: -FROM ubuntu:14.04
  +FROM ubuntu:17.04
   
   RUN apt-get -y update && \
  -    apt-get install -y curl git-core mingw-w64 xz-utils build-essential gcc-multilib wget unzip
  -
  -RUN mkdir -p /opt/mingw && \
  -    curl -SL http://downloads.sourceforge.net/mingw-w64/i686-w64-mingw32-gcc-4.7.2-release-linux64_rubenvb.tar.xz | \
  -    tar -xJC /opt/mingw && \
  -    echo "export PATH=\$PATH:/opt/mingw/mingw32/bin" >> /etc/rubybashrc
  -
  -RUN mkdir -p /opt/mingw && \
  -    curl -SL http://downloads.sourceforge.net/mingw-w64/x86_64-w64-mingw32-gcc-4.7.2-release-linux64_rubenvb.tar.xz | \
  -    tar -xJC /opt/mingw && \
  -    echo "export PATH=\$PATH:/opt/mingw/mingw64/bin" >> /etc/rubybashrc
  +    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
  
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: 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
  