anchor.diff:  -record(state, {
   }).
   
  --define(new_metadata_appeared,new_metadata_appeared).
   -define(BUCKET_TYPE_PREFIX, {core, bucket_types}).
   
   -include_lib("riak_ql/include/riak_ql_ddl.hrl").
  
positive.code: stop_current_compilation(Compiler_pid) ->
      case is_process_alive(Compiler_pid) of
          true ->
              exit(Compiler_pid, ?new_metadata_appeared),
              ok = flush_exit_message(Compiler_pid);
          false ->
              ok
  
negative.code:     % success
      _ = riak_kv_compile_tab:update_state(Pid, compiled),
      {noreply, State};
  handle_info({'EXIT', _, bucket_type_changed_mid_compile}, State) ->
      % this means that the process was interrupted while compiling by an update
      % to the metadata
      {noreply, State};
  