无法创建索引

ValueError: need at least one array to concatenate

/root/miniconda3/envs/rvc/lib/python3.10/site-packages/torch/optim/lr_scheduler.py:138: UserWarning: Detected call of `lr_scheduler.step()` before `optimizer.step()`. In PyTorch 1.1.0 and later, you should call them in the opposite order: `optimizer.step()` before `lr_scheduler.step()`.  Failure to do this will result in PyTorch skipping the first value of the learning rate schedule. See more details at https://pytorch.org/docs/stable/optim.html#how-to-adjust-learning-rate
  warnings.warn("Detected call of `lr_scheduler.step()` before `optimizer.step()`. "
Traceback (most recent call last):
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/gradio/routes.py", line 393, in run_predict
    output = await app.get_blocks().process_api(
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/gradio/blocks.py", line 1108, in process_api
    result = await self.call_function(
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/gradio/blocks.py", line 929, in call_function
    prediction = await anyio.to_thread.run_sync(
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/anyio/to_thread.py", line 31, in run_sync
    return await get_asynclib().run_sync_in_worker_thread(
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 937, in run_sync_in_worker_thread
    return await future
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 867, in run
    result = context.run(func, *args)
  File "/root/miniconda3/envs/rvc/lib/python3.10/site-packages/gradio/utils.py", line 490, in async_iteration
    return next(iterator)
  File "/root/autodl-tmp/Retrieval-based-Voice-Conversion-WebUI/infer-web.py", line 898, in train1key
    big_npy = np.concatenate(npys, 0)
  File "<__array_function__ internals>", line 180, in concatenate
ValueError: need at least one array to concatenate

Start at infer-web.py line 898 in train1key, where np.concatenate receives npys, and trace how those arrays are collected during index creation. Reproduce the failure with the reported setup and determine why no arrays are available. Done means index creation handles the empty-input case appropriately and the failing path is covered by a test or verified reproduction.