astropy: crash/bug when reading table meta-data containing object array written with serialize_meta=True to HDF5 file

Description

Please see the code below that crashes unexpectedly after the first run, i.e. typically at the second run. I’m puzzled by the behavior. Note that the code doesn’t crash if a.) bands would be a byte string array, b.) serialize_meta was False or c.) a table was written where serialize_meta was True before reading the table (that’s why the first run doesn’t crash).

I’m sorry if what I’m doing is not supported. In any case, that the code just crashes with a segmentation fault is puzzling. I’ve run the code on 2 machines and 3 different virtual environments and they all crashed eventually.

Expected behavior

No crash and consistent output, i.e. OrderedDict([('bands', array(['g', 'r', 'i'], dtype=object))]), when running the code repeatedly.

How to Reproduce

I ran the following code in a virtual environment on Fedora 38 with python 3.11 and packages installed via pip. Here’s the minimal requirements.txt.

astropy==5.2.2 h5py==3.8.0 numpy==1.24.3 packaging==23.1 pyerfa==2.0.0.3 PyYAML==6.0

The following code crashes after running the script a second time. In other words, if I run the script once, it works fine and outputs the expected result. But when running it again, it typically crashes with a segmentation fault. Sometimes, the second and later run give a wrong result, i.e. OrderedDict([(‘bands’, array([‘R’, ‘r’, ‘i’], dtype=object))]).

from astropy.table import Table
import numpy as np
from pathlib import Path

table = Table(np.arange(5))
table.meta['bands'] = np.array(['g', 'r', 'i'], dtype=object)

path = Path('test.hdf5')
if not path.exists():
    table.write(path, serialize_meta=True)
print(Table.read(path).meta)

Versions

Linux-6.2.14-300.fc38.x86_64-x86_64-with-glibc2.37 Python 3.11.3 (main, Apr 5 2023, 00:00:00) [GCC 13.0.1 20230401 (Red Hat 13.0.1-0)] astropy 5.2.2 Numpy 1.24.3 pyerfa 2.0.0.3