mypy fixup, error message compat for 32bit builds

Author: jbrockmendel

pandas/io/parsers/arrow_parser_wrapper.py

@@ -330,7 +330,8 @@ def read(self) -> DataFrame:
                     # We cast here in case the user passed "category" in
                     #  order to get the correct dtype.categories.dtype
                     #  e.g. test_categorical_dtype_utf16
-                    new_dtype[key] = StringDtype(na_value=np.nan)
+                    sdt = StringDtype(na_value=np.nan)
+                    new_dtype[key] = sdt  # type: ignore[assignment]
                     frame[key] = frame[key].astype(new_dtype[key])
 
             new_dtype.update(old_dtype)

pandas/tests/io/parser/test_na_values.py

@@ -802,11 +802,11 @@ def test_bool_and_nan_to_int(all_parsers):
 False
 """
     msg = (
-        "cannot safely convert passed user dtype of int64 for "
+        "cannot safely convert passed user dtype of int(64|32) for "
         "<class 'numpy.bool'> dtyped data in column 0 due to NA values"
     )
     if parser.engine == "python":
-        msg = "Unable to convert column 0 to type int64"
+        msg = "Unable to convert column 0 to type int(64|32)"
     elif parser.engine == "pyarrow":
         msg = r"cannot convert NA to integer"
     with pytest.raises(ValueError, match=msg):