anchor.diff:  
   %%@hidden
   runtime_expr_transform(ExprParseTree, Transforms) ->
  -    erl_syntax:revert(
  -      erl_syntax:copy_pos(
  -        ExprParseTree,
  -        apply_transforms(ExprParseTree, Transforms))).
  +    with_increased_backtrace_depth(
  +      fun() ->
  +              erl_syntax:revert(
  +                erl_syntax:copy_pos(
  +                  ExprParseTree,
  +                  apply_transforms(ExprParseTree, Transforms)))
  +      end).
   
   %%@hidden
   runtime_exprs_transform(ExprParseTrees, Transforms) ->
  -    [erl_syntax:revert(
  -       erl_syntax:copy_pos(
  -         ExprParseTree,
  -         apply_transforms(ExprParseTree, Transforms)))
  -     || ExprParseTree <- ExprParseTrees].
  +    with_increased_backtrace_depth(
  +      fun() ->
  +              [erl_syntax:revert(
  +                 erl_syntax:copy_pos(
  +                   ExprParseTree,
  +                   apply_transforms(ExprParseTree, Transforms)))
  +               || ExprParseTree <- ExprParseTrees]
  +      end).
   
   apply_transforms(ParseTree, Transforms) ->
       lists:foldl(fun apply_transform/2, ParseTree, Transforms).
  
positive.code: 
  %%@hidden
  erl_prettypr_format_nl(Form) ->
      [erl_prettypr:format(Form), "\n"].
  
  %%@hidden
  runtime_fn_transform(FnName, FnParseTree) ->
  
negative.code: 
  %%@hidden
  parse_transform(Forms, Opts) ->
      with_increased_backtrace_depth(
        fun() ->
                transform_forms(Forms, Opts)
        end).
  
  %%@hidden
  mk_fn(Name, Fun) -> error_invalid_call(mk_fn, [Name, Fun]).
  