anchor.diff:  
   -spec add_code_path(string(), string()) -> ok | {error, bad_directory}.
   add_code_path(Name, Version) ->
  -  PluginPath = ?PLUGIN_DIR ++ "/" ++ get_file_slug(Name, Version) ++ "/ebin",
  +  PluginPath = plugin_dir() ++ "/" ++ get_file_slug(Name, Version) ++ "/ebin",
     case code:add_path(PluginPath) of
       true -> ok;
       Else ->
  
positive.code:   % gunzip
    log("unzipped"),
    TarData = zlib:gunzip(GzData),
    ok = filelib:ensure_dir(?PLUGIN_DIR),
    % untar
    erl_tar:extract({binary, TarData}, [{cwd, ?PLUGIN_DIR}, keep_old_files]).
  
  
  % downloads a pluygin .tar.gz into a local plugins directory
  
negative.code:       fun load_config_file/1,
        filelib:wildcard(
          filename:join(
            [plugin_dir(), get_file_slug(Name, Version),
             "priv", "default.d", "*.ini"]))).
  
  -spec load_config_file(string()) -> ok.
  