In [1]: import pandas as pd

In [2]: df = pd.DataFrame({"a": [1, 2], "c": [0, 2], "d": ["c", "a"]})

In [3]: df.iloc[:, df['c']]  # works fine
Out[3]:
   a  d
0  1  c
1  2  a

In [4]: df = pd.DataFrame({"a": [1, 2], "c": [0, 2], "d": ["c", "a"]}).convert_dtypes(dtype_backend='pyarrow')

In [5]: df.iloc[:, df['c']]  # now, it raises
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[5], line 1
----> 1 df.iloc[:, df['c']]

File ~/pandas-dev/pandas/core/indexing.py:1189, in _LocationIndexer.__getitem__(self, key)
   1187     if self._is_scalar_access(key):
   1188         return self.obj._get_value(*key, takeable=self._takeable)
-> 1189     return self._getitem_tuple(key)
   1190 else:
   1191     # we by definition only have the 0th axis
   1192     axis = self.axis or 0

File ~/pandas-dev/pandas/core/indexing.py:1692, in _iLocIndexer._getitem_tuple(self, tup)
   1691 def _getitem_tuple(self, tup: tuple):
-> 1692     tup = self._validate_tuple_indexer(tup)
   1693     with suppress(IndexingError):
   1694         return self._getitem_lowerdim(tup)

File ~/pandas-dev/pandas/core/indexing.py:975, in _LocationIndexer._validate_tuple_indexer(self, key)
    973 for i, k in enumerate(key):
    974     try:
--> 975         self._validate_key(k, i)
    976     except ValueError as err:
    977         raise ValueError(
    978             f"Location based indexing can only have [{self._valid_types}] types"
    979         ) from err

File ~/pandas-dev/pandas/core/indexing.py:1613, in _iLocIndexer._validate_key(self, key, axis)
   1610         raise IndexError(f".iloc requires numeric indexers, got {arr}")
   1612     # check that the key does not exceed the maximum size of the index
-> 1613     if len(arr) and (arr.max() >= len_axis or arr.min() < -len_axis):
   1614         raise IndexError("positional indexers are out-of-bounds")
   1615 else:

AttributeError: 'ArrowExtensionArray' object has no attribute 'max'