anchor.diff:  -spec build (list()) -> boolean().
   build (Conf) ->
       filelib:ensure_dir(kf(dest, Conf)),
  -    AppDirs = app_dirs(kf(apps, Conf)),
  +    AppDirs = [Path || Path <- kf(apps,Conf), filelib:is_dir(Path)],
       IncludePaths = lists:flatmap(fun includes/1, AppDirs),
   
       Fun   = fun (AppDir, Acc) -> build_apps(Conf, IncludePaths, AppDir, Acc) end,
  
positive.code:               ([A,B,C,D]) ->
                    fmt("['~s','~s','~s','~s']", [html_encode(X) || X <- [A,B,C,D]])
            end,
            lists:sort(fun sort_index/2, lists:map(F, FIndex))),
  
      Js = fmt("var index = [~s];",
               [string:join([[C || C <- I, C /= $\n, C /= $\r] || I <- Index], ",")]),
  
      ok = file:write_file(jname(kf(dest,Conf), "erldocs_index.js"), Js).
  
  %% Note: handles both erlref and cref types
  render (App, Mod, Xml, Types, Conf) ->
  
negative.code:     %% Output XML files to destination folder
      %% This prevents from polluting the source files
      TmpRoot = jname(kf(dest,Conf), ?ERLDOCS_SPECS_TMP),
      XMLDir  = jname(TmpRoot, bname(AppDir)),
      filelib:ensure_dir(XMLDir ++ "/"),
  
      lists:foreach(fun (File) -> gen_type_specs(TmpRoot, IncludePaths, File) end, ErlFiles),
  