>>> ak.concatenate([ak.Array([i])[:, np.newaxis] for i in range(127)], axis=1)
<Array [[0, 1, 2, 3, 4, ..., 122, 123, 124, 125, 126]] type='1 * 127 * int64'>

>>> ak.concatenate([ak.Array([i])[:, np.newaxis] for i in range(128)], axis=1)
Traceback (most recent call last):
...
KeyError: ('awkward_UnionArray_regular_index_getsize', <class 'numpy.int64'>, <class 'numpy.int64'>)

This error occurred while calling

    ak.concatenate(
        [<Array [[0]] type='1 * 1 * int64'>, <Array [[1]] type='1 * 1 * int64...
        axis = 1
    )