anchor.diff:  
   RUN mkdir -p /usr/share/maven /usr/share/maven/ref \
       && curl -fsSL http://apache.osuosl.org/maven/maven-3/$MAVEN_VERSION/binaries/apache-maven-$MAVEN_VERSION-bin.tar.gz \
  -      | tar -xzC /usr/share/maven \
  +      | tar -xzC /usr/share/maven --strip-components=1 \
       && ln -s /usr/share/maven/bin/mvn /usr/bin/mvn
   
   ENV MAVEN_HOME /usr/share/maven
  
positive.code: 
  # do all in one step
  RUN apk upgrade --update && \
      apk add --update curl ca-certificates bash git && \
      for pkg in glibc-${GLIBC_VERSION} glibc-bin-${GLIBC_VERSION} glibc-i18n-${GLIBC_VERSION}; do curl -sSL https://github.com/andyshinn/alpine-pkg-glibc/releases/download/${GLIBC_VERSION}/${pkg}.apk -o /tmp/${pkg}.apk; done && \
      apk add --allow-untrusted /tmp/*.apk && \
      rm -v /tmp/*.apk && \
  
negative.code: COPY settings-docker.xml /usr/share/maven/ref/
  ADD pom.xml /maven/
  RUN cd /maven \
      && mvn install
  
  VOLUME "$USER_HOME_DIR/.m2"
  
  