Tensor.item() cannot be called on meta tensors

[sowbug]

Ubuntu 24.04, Python 3.11. Put some test images in input/ and ran python batch-alpha2.py in venv after following setup steps, and I get this output:

$ python batch-alpha2.py
2024-10-24 00:40:59,151 INFO: Arguments: Namespace(glob=None, filelist=None, input_folder=False, prompt='Please provide a detailed description of the image.', prompt_file=None, image_seq_length=1, batch_size=1, greedy=False, temperature=0.5, top_p=0.9, top_k=10, max_new_tokens=300, num_workers=4, model='fancyfeast/llama-joycaption-alpha-two-hf-llava', print_captions=False, print_captioning_status=False, overwrite=True, prepend_string='', append_string='')
2024-10-24 00:40:59,151 INFO: No image sources provided. Defaulting to the 'input' folder.
2024-10-24 00:40:59,151 INFO: Adding 57 images from the default input folder '[...]/input'.
2024-10-24 00:40:59,151 INFO: Total images found: 57
2024-10-24 00:40:59,151 INFO: Overwrite option enabled; all images will be processed.
2024-10-24 00:41:00,367 INFO: We will use 90% of the memory on device 0 for storing the model, and 10% for the buffer to avoid OOM. You can set `max_memory` in to a higher value to use more memory (at your own risk).
2024-10-24 00:41:00,398 WARNING: The model weights are not tied. Please use the `tie_weights` method before using the `infer_auto_device` function.
Loading checkpoint shards: 100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 4/4 [00:00<00:00,  4.19it/s]
2024-10-24 00:41:01,580 WARNING: Some parameters are on the meta device because they were offloaded to the cpu.
Captioning images...:   0%|                                                                                                                                           | 0/57 [00:00<?, ?it/s]2024-10-24 00:41:01,902 ERROR: Generation failed: Tensor.item() cannot be called on meta tensors
Captioning images...:   2%|██▎                                                                                                                                | 1/57 [00:00<00:18,  3.11it/s]2024-10-24 00:41:01,904 ERROR: Generation failed: Tensor.item() cannot be called on meta tensors

Note that I used python batch-alpha2.py because py batch-alpha2.py gave a different error:

$ py batch-alpha2.py
/usr/bin/py:29: SyntaxWarning: invalid escape sequence '\.'
  if re.match('np(\..*)?$', raw_module_name):
/usr/bin/py:31: SyntaxWarning: invalid escape sequence '\.'
  elif re.match('pd(\..*)?$', raw_module_name):
Traceback (most recent call last):
  File "/usr/bin/py", line 167, in <module>
    result = eval(args.expression)
             ^^^^^^^^^^^^^^^^^^^^^
  File "<string>", line 1, in <module>
    batch-alpha2.py
NameError: name 'batch' is not defined

I did install pythonpy on my non-venv main system, but that doesn't seem to help.