anchor.diff:              ErtsDir = filename:join([Prefix, "erts-" ++ ErtsVersion]),
               LocalErts = filename:join([OutputDir, "erts-" ++ ErtsVersion]),
               {OsFamily, _OsName} = os:type(),
  -            case filelib:is_dir(ErtsDir) of
  +            case ec_file:is_dir(ErtsDir) of
                   false ->
                       ?RLX_ERROR({specified_erts_does_not_exist, ErtsVersion});
                   true ->
  
positive.code: -spec create_output_dir(file:name()) ->
                                 ok | {error, Reason::term()}.
  create_output_dir(OutputDir) ->
      case filelib:is_dir(OutputDir) of
          false ->
              case rlx_util:mkdir_p(OutputDir) of
                  ok ->
  
negative.code:         true ->
              ec_file:remove(TargetDir);
          false ->
              case ec_file:is_dir(TargetDir) of
                  true ->
                      ok = ec_file:remove(TargetDir, [recursive]);
                  false ->
  