anchor.diff:      curl --fail --silent --location --retry 3 $tarball > /opt/tarsnap.tgz && \
       expected=`gpg --decrypt /opt/tarsnap.asc | awk '{print $4}'` && \
       actual=`shasum -a 256 /opt/tarsnap.tgz | awk '{print $1}'` && \
  +    echo '=====================================' && \
  +    echo 'Expected hash = $expected' && \
  +    echo 'Tarball hash  = $actual' && \
  +    echo '=====================================' && \
       if [ $actual != $expected ]; then echo 'Hash mismatch!'; exit 1; fi && \
       mkdir /opt/tarsnap && \
       cat /opt/tarsnap.tgz | tar -xz -C /opt/tarsnap --strip-components=1 && \
  
positive.code:     make all && \
      make install && \
      rm -fr /opt/* && \
      apt-get -qq -y --auto-remove remove curl gcc libc6-dev make libssl-dev zlib1g-dev e2fslibs-dev gnupg2 && \
      apt-get clean
  
negative.code: 
  MAINTAINER Andrew Heald <andrew@heald.uk>
  
  ENTRYPOINT tarsnap
  
  ARG hash
  ARG tarball
  ARG dependencies=curl gcc libc6-dev make libssl-dev zlib1g-dev e2fslibs-dev gnupg2
  
  RUN apt-get -qq update && \
      apt-get -qq -y install $dependencies
  
  ADD tarsnap-signing-key-2016.asc /opt/
  
  