anchor.diff:  RUN bash -lc 'rbenv shell 2.4.5 && gem install bundler --version 1.16.2'
   RUN bash -lc 'rbenv shell 2.5.0 && gem install bundler --version 1.16.2'
   RUN bash -lc 'rbenv shell 2.5.1 && gem install bundler --version 1.16.2'
  +RUN bash -lc 'rbenv shell 2.5.5 && gem install bundler --version 1.17.3'
   RUN bash -lc 'rbenv shell 2.6.3 && gem install bundler --version 2.0.1'
   RUN bash -lc 'rbenv shell 2.6.4 && gem install bundler --version 2.0.1'
   
  
positive.code: FROM ubuntu:disco-20190718
  ENV LANG=C.UTF-8
  
  RUN apt-get update && apt-get install -y --no-install-recommends \
  
negative.code: RUN bash -lc 'rbenv install 2.4.5'
  RUN bash -lc 'rbenv install 2.5.0'
  RUN bash -lc 'rbenv install 2.5.1'
  RUN bash -lc 'rbenv install 2.5.5'
  RUN bash -lc 'rbenv install 2.6.3'
  RUN bash -lc 'rbenv install 2.6.4'
  
  