anchor.diff:      libuuid-devel \
       gsm-devel
   
  +ENV RUN_PKG_LIST pjproject jansson neon unixODBC vorbis
  +
   # install dependencies
  -RUN yum -q makecache && yum install tar epel-release -y && yum install -q -y $PKG_LIST
  +RUN yum -q makecache && yum install tar epel-release -y && yum install -q -y $DEV_PKG_LIST $RUN_PKG_LIST
   
   # obtain and extract the source
   WORKDIR $TARGET_DIR
  
positive.code: # clean up
  WORKDIR $TARGET_DIR
  RUN rm -rf $ASTVERSION
  RUN yum remove -y -q tar $PKG_LIST && yum autoremove -y && yum clean all
  
  # start the system
  WORKDIR /usr/sbin
  
negative.code: ENV DOWNLOAD_URL http://downloads.asterisk.org/pub/telephony/certified-asterisk
  ENV ASTVERSION certified-asterisk-13.1-cert2
  ENV TARGET_DIR /usr/src/
  ENV DEV_PKG_LIST automake \
      gcc \
      gcc-c++ \
      ncurses-devel \
  