# Buggy code
def _calc_bool_index_param(
    cls, input_index_value: IndexValue, pd_index: pd.Index, inp, index, axis: int
) -> Dict:
    param = dict()
    if input_index_value.has_value():
        if isinstance(index, np.ndarray):
            filtered_index = pd_index[index]
            param["shape"] = len(filtered_index)
            param["index_value"] = parse_index(filtered_index, store_data=axis == 1)
            if axis == 1:
                param["dtypes"] = inp.dtypes[index]
        else:
            # tensor, cannot be indexer on axis 1
            assert axis == 0
            param["shape"] = np.nan
            param["index_value"] = parse_index(
                pd.Index([], dtype=pd_index.dtype), inp, index, store_data=False
            )
    else:
        assert axis == 0
        if isinstance(index, np.ndarray):
            param["shape"] = index.sum()
        else:
            param["shape"] = np.nan
        param["index_value"] = parse_index(pd_index, inp, index, store_data=False)

    return param


# Traceback (AttributeError)
In [3]: import pandas as pd

In [4]: data = pd.DataFrame(np.arange(20).reshape((4, 5)) + 1, columns=['a', 'b', 'c', 'd', 'e'])

In [6]: df = md.DataFrame(data)

In [7]: df.groupby(['a','b']).size().execute()
Unexpected exception occurred in enter_build_mode.<locals>.inner.
Traceback (most recent call last):
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 353, in _wrapped
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 493, in inner
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/scheduler/graph.py", line 633, in prepare_graph
self._target_tileable_datas + fetch_tileables, tileable_graph)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 399, in _wrapped
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 493, in inner
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 350, in build
tileables, tileable_graph=tileable_graph)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 399, in _wrapped
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 493, in inner
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 263, in build
self._on_tile_failure(tileable_data.op, exc_info)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 302, in inner
raise exc_info[1].with_traceback(exc_info[2]) from None
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 243, in build
tiled = self._tile(tileable_data, tileable_graph)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 338, in _tile
return super()._tile(tileable_data, tileable_graph)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 203, in _tile
tds = on_tile(tileable_data.op.outputs, tds)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/scheduler/graph.py", line 615, in on_tile
return self.context.wraps(handler.dispatch)(first.op)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/context.py", line 69, in h
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/utils.py", line 399, in _wrapped
return func(*args, **kwargs)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/tiles.py", line 119, in dispatch
tiled = op_cls.tile(op)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/dataframe/groupby/aggregation.py", line 481, in tile
return cls._tile_with_tree(op)
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/dataframe/groupby/aggregation.py", line 412, in _tile_with_tree
index = out_df.index_value.to_pandas()
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/dataframe/core.py", line 283, in to_pandas
return self._index_value.to_pandas()
File "/Users/hekaisheng/Documents/mars_dev/mars/mars/dataframe/core.py", line 197, in to_pandas
sortorder=self._sortorder, names=self._names)
AttributeError: _sortorder

# Fixed code
def _calc_bool_index_param(
    cls, input_index_value: IndexValue, pd_index: pd.Index, inp, index, axis: int
) -> Dict:
    param = dict()
    if input_index_value.has_value():
        if isinstance(index, np.ndarray):
            filtered_index = pd_index[index]
            param["shape"] = len(filtered_index)
            param["index_value"] = parse_index(filtered_index, store_data=axis == 1)
            if axis == 1:
                param["dtypes"] = inp.dtypes[index]
        else:
            # tensor, cannot be indexer on axis 1
            assert axis == 0
            param["shape"] = np.nan
            param["index_value"] = parse_index(
                pd.Index([], dtype=pd_index.dtype), inp, index, store_data=False
            )
    else:
        assert axis == 0
        if isinstance(index, np.ndarray):
            param["shape"] = int(index.sum())
        else:
            param["shape"] = np.nan
        param["index_value"] = parse_index(pd_index, inp, index, store_data=False)

    return param