anchor.diff:  
   WORKDIR /tmp
   
  -# install boost 1.62+
  +# set boost envs
   ARG boost_version=1.62.0
   ARG boost_dir=boost_1_62_0
   ARG boost_sha256_sum=440a59f8bc4023dbe6285c9998b0f7fa288468b889746b1ef00e8b36c559dce1
  
positive.code: 
  RUN apt-get update && apt-get install -y --no-install-recommends \
    ca-certificates \
    wget \
    g++ \
    git \
  
negative.code:   --with-system \
    --with-thread
  
  # install boost
  RUN wget http://downloads.sourceforge.net/project/boost/boost/${boost_version}/${boost_dir}.tar.gz \
    && echo "${boost_sha256_sum}  ${boost_dir}.tar.gz" | sha256sum -c \
    && tar xfz ${boost_dir}.tar.gz \
  