autopkgtests fail on 32 bit architectures

[Jelmer Vernooij]

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/breezy/commit.py", line 442, in _commit
    self.builder.finish_inventory()
  File "/usr/lib/python3/dist-packages/breezy/bzr/vf_repository.py", line 230, in finish_inventory
    self.parents)
  File "/usr/lib/python3/dist-packages/breezy/bzr/groupcompress_repo.py", line 947, in add_inventory_by_delta
    new_inv = self._create_inv_from_null(delta, new_revision_id)
  File "/usr/lib/python3/dist-packages/breezy/bzr/groupcompress_repo.py", line 913, in _create_inv_from_null
    parent_id_basename_dict, maximum_size=serializer.maximum_size)
  File "/usr/lib/python3/dist-packages/breezy/bzr/inventory.py", line 1878, in _populate_from_dicts
    search_key_func=search_key_func)
  File "/usr/lib/python3/dist-packages/breezy/bzr/chk_map.py", line 249, in from_dict
    search_key_func=search_key_func)
  File "/usr/lib/python3/dist-packages/breezy/bzr/chk_map.py", line 279, in _create_directly
    node._compute_search_prefix()
  File "/usr/lib/python3/dist-packages/breezy/bzr/chk_map.py", line 941, in _compute_search_prefix
    search_keys = [self._search_key_func(key) for key in self._items]
  File "/usr/lib/python3/dist-packages/breezy/bzr/chk_map.py", line 941, in <listcomp>
    search_keys = [self._search_key_func(key) for key in self._items]
SystemError: <built-in function _search_key_255> returned a result with an error set
}}}

Traceback (most recent call last):
OverflowError: Python int too large to convert to C long