anchor.diff:  
   WORKDIR /mastodon
   
  -RUN echo "@edge https://nl.alpinelinux.org/alpine/edge/main" >> /etc/apk/repositories \
  - && echo "@edge https://nl.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories \
  - && apk -U upgrade \
  +RUN apk -U upgrade \
    && apk add -t build-dependencies \
       build-base \
       icu-dev \
  
positive.code:     file \
      git \
      icu-libs \
      imagemagick@edge \
      libidn \
      libpq \
      nodejs-npm@edge \
      nodejs@edge \
      protobuf \
      su-exec \
      tini \
      yarn@edge \
   && update-ca-certificates \
   && wget -O libiconv.tar.gz "http://ftp.gnu.org/pub/gnu/libiconv/libiconv-$LIBICONV_VERSION.tar.gz" \
   && echo "$LIBICONV_DOWNLOAD_SHA256 *libiconv.tar.gz" | sha256sum -c - \
  
negative.code: FROM ruby:2.4.1-alpine3.6
  
  LABEL maintainer="https://github.com/tootsuite/mastodon" \
        description="A GNU Social-compatible microblogging server"
  