[BUG]: standalone rag pipeline fails with `ValueError: No objects to concatenate`

[dagardner-nv]

Version

24.06

Which installation method(s) does this occur on?

Source

Describe the bug.

Rag pipeline failing immediately

Minimum reproducible example

python examples/llm/main.py --log_level=debug rag pipeline

Relevant log output

Click here to see error details

Traceback (most recent call last):
  File "/home/dagardner/work/morpheus/examples/llm/main.py", line 33, in 
    run_cli()
  File "/home/dagardner/work/morpheus/examples/llm/main.py", line 29, in run_cli
    cli(obj={}, auto_envvar_prefix='MORPHEUS_LLM', show_default=True, prog_name="morpheus_llm")
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/click/core.py", line 1078, in main
    rv = self.invoke(ctx)
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
  File "/home/dagardner/work/morpheus/examples/llm/rag/run.py", line 89, in pipeline
    return standalone(**kwargs)
  File "/home/dagardner/work/morpheus/examples/llm/rag/standalone_pipeline.py", line 138, in standalone
    responses = concat_dataframes(messages)
  File "/home/dagardner/work/morpheus/morpheus/utils/concat_df.py", line 54, in concat_dataframes
    return pd.concat(all_meta)
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/pandas/util/_decorators.py", line 331, in wrapper
    return func(*args, **kwargs)
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/pandas/core/reshape/concat.py", line 368, in concat
    op = _Concatenator(
  File "/home/dagardner/work/conda/envs/morpheus/lib/python3.10/site-packages/pandas/core/reshape/concat.py", line 425, in __init__
    raise ValueError("No objects to concatenate")
ValueError: No objects to concatenate

Full env printout

Click here to see environment details

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Other/Misc.

No response

Code of Conduct

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• [X] I have searched the open bugs and have found no duplicates for this bug report