anchor.diff: -FROM debian:buster
  +FROM debian:stretch
   ENV LANG C.UTF-8
   ENV LANGUAGE C.UTF-8
   ENV LC_ALL C.UTF-8
  
positive.code:     && make install
  
  
  FROM debian:buster
  ENV LANG C.UTF-8
  ENV LANGUAGE C.UTF-8
  ENV LC_ALL C.UTF-8
  
negative.code:     && make install \
      && cd /app/deps \
      && rm -Rf jansson-${JANSSON_VERSION}
  ARG LIBJWT_VERSION="1.9.0"
  RUN curl -o libjwt-v${LIBJWT_VERSION}.tar.gz -L \
          "https://github.com/benmcollins/libjwt/archive/v${LIBJWT_VERSION}.tar.gz" \
      && tar -xvzf libjwt-v${LIBJWT_VERSION}.tar.gz \
  