anchor.diff:  handle_call(fetch_errors, _From, State) ->
       {reply, State#state.errors, State};
   handle_call(info, From, State) ->
  -    spawn_link(fun() ->
  -        ErrorCount = dict:size(State#state.errors),
  -        RetardsCount = length(State#state.retards),
  -        UpstreamCount = dict:size(State#state.upstream),
  -        TbdCount = dict:size(State#state.tbd),
  -        Info = [
  -            {errors, ErrorCount},
  -            {retards, RetardsCount},
  -            {upstream, UpstreamCount},
  -            {tbd, TbdCount}
  -        ],
  -        gen_server:reply(From, Info)
  +    spawn(fun() ->
  +        gen_server:reply(From, [
  +            {errors, dict:size(State#state.errors)},
  +            {retards, length(State#state.retards)},
  +            {upstream, dict:size(State#state.upstream)},
  +            {tbd, dict:size(State#state.tbd)}
  +        ])
       end),
       {noreply, State};
   handle_call(_Req, _From, State) ->
  
positive.code: 
  -define(TICK_INTERVAL_MILLIS, 10000).
  -define(REFRESH_INTERVAL_MICROS, 60 * 60* 1000* 1000 * 1000).
  -record(state, { retards =[], upstream = dict:new(), tbd = dict:new(), errors = dict:new() }).
  
  -compile(export_all).
  % -----------------------------------------------------------------------------
  
negative.code: handle_info(tick, State) ->
      ThisPid = self(),
      {Now, UpstreamBaseUrls} = upstream_to_be_refreshed(State),
      Pids = case UpstreamBaseUrls of
          [UpstreamBaseUrl| _] -> 
              Pid = spawn_link(fun() -> refresh_upstream(ThisPid, Now, UpstreamBaseUrl) end),
              [Pid];
          [] -> 
              case dict:fetch_keys(State#state.tbd) of
                  [] ->  
                      timer:send_after(?TICK_INTERVAL_MILLIS, tick),
                      [];
                  [{AuthorAndModule, Version} = Coords|_] -> 
                      BaseUrl = dict:fetch(Coords, State#state.tbd),
                      Pid = spawn_link(fun() -> fetch_and_store_tarball(ThisPid, Now, BaseUrl, AuthorAndModule, Version) end),
                      [Pid]
              end
      end,
      {noreply, State#state{ pids = lists:append(Pids, State#state.pids)}};
  
  handle_info({upstream_metadata, At, UpstreamBaseUrl, VersionsFromUpstream}, State) ->
      Unknown = lists:filter(fun({BaseUrl, {{Author, Module}, Version}}) ->
  