`test_boolean_casting` failing

[tswast]

_____________________________ test_boolean_casting _____________________________

alltypes = BigQueryTable[table]
  name: ibis-gbq.testing.functional_alltypes
  schema:
    index : int64
    Unnamed_0 : int64
  ...4
    date_string_col : string
    string_col : string
    timestamp_col : timestamp
    year : int64
    month : int64

    def test_boolean_casting(alltypes):
        t = alltypes
        expr = t.groupby(k=t.string_col.nullif("1") == "9").count()
        result = expr.execute().set_index("k")
        count = result["count"]
>       assert count.loc[False] == 5840

tests/system/test_client.py:714: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
../../../.local/lib/python3.8/site-packages/pandas/core/indexing.py:931: in __getitem__
    return self._getitem_axis(maybe_callable, axis=axis)
../../../.local/lib/python3.8/site-packages/pandas/core/indexing.py:1163: in _getitem_axis
    self._validate_key(key, axis)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <pandas.core.indexing._LocIndexer object at 0x7f512c837900>, key = False
axis = 0

    @doc(_LocationIndexer._validate_key)
    def _validate_key(self, key, axis: int):
        # valid for a collection of labels (we check their presence later)
        # slice of labels (where start-end in labels)
        # slice of integers (only if in the labels)
        # boolean not in slice and with boolean index
        if isinstance(key, bool) and not is_bool_dtype(self.obj.index):
>           raise KeyError(
                f"{key}: boolean label can not be used without a boolean index"
            )
E           KeyError: 'False: boolean label can not be used without a boolean index'