RuntimeError "Unexpected key" when running checkpoint_converters script convert_got_nemo_to_mcore.py
Hi, try to follow up here: I think we have few different version of NeMo checkpoints at the moment. The current script works for more recent nemo checkpoints but maybe not 2B. The error is not caused by the input NeMo checkpoint. It is caused by this change in the output mcore checkpoint, i.e., these two sets of weight and bias have been renamed according to the module_name_rewrite_list given in https://github.com/NVIDIA/Megatron-LM/blob/e33c8f78a35765d5aa37475a144da60e8a2349d1/megatron/core/inference/gpt/state_dict_hooks.py#L116-L119 @yaoyu-33 Please let me know if you need more info about this issue or the pull request. Thanks! Hi sorry for the delay. Yes, it makes sense now. added a comment in your PR.
Can you sign your PR when you commit by `commit -sm "commit msg"` @yaoyu-33 No problem. Thank you for the response! I addressed your comment in my PR. I signed my PR and rebased it onto the latest main. @yaoyu-33 Gentle ping. Please let me know if you have any other comment. Thanks! hi @renweizhukov  we should probably change others then. We try to keep the core args the same (using _) across the checkpoint_converters folder. 

After this change, I think it's good to go @yaoyu-33 Make sense. I have changed the hyphens to underscores for the two other command-line options. @yaoyu-33 I have made the change per your suggestion. Could you please take a look? Thanks! > @yaoyu-33 I have made the change per your suggestion. Could you please take a look? Thanks!

will get it merged today @yaoyu-33 Just wonder if we have merged the pull request. there were some ci issues last week, finally merged. Great. Thank you!
**Describe the bug**

RuntimeError "Unexpected key" when running checkpoint_converters script convert_got_nemo_to_mcore.py

**Steps/Code to reproduce bug**

Follow the instructions given in https://docs.nvidia.com/nemo-framework/user-guide/latest/modelalignment/dpo.html to convert a GPT-2B checkpoint to Megatron-Core checkpoint.

1. Download the 2B checkpoint.

```
wget https://huggingface.co/nvidia/GPT-2B-001/resolve/main/GPT-2B-001_bf16_tp1.nemo
```

2. Extract the NeMo file to a folder.

```
mkdir model_checkpoint && tar -xvf GPT-2B-001_bf16_tp1.nemo -C model_checkpoint
```

3. Run the script to convert from old NeMo checkpoint to Megatron-Core checkpoint. The original linked script [convert_nemo_gpt_to_mcore.py](https://github.com/NVIDIA/NeMo/blob/86b198ff93438d454f9c7f3550bcfb7d4e59feab/scripts/nlp_language_modeling/convert_nemo_gpt_to_mcore.py) has been replaced with [convert_gpt_nemo_to_mcore.py](https://github.com/renweizhukov/NeMo/blob/main/scripts/checkpoint_converters/convert_gpt_nemo_to_mcore.py).

```
python convert_gpt_nemo_to_mcore.py --input_name_or_path ./model_checkpoint --output_path ./mcore_gpt.nemo
```

4. Hit the following `RuntimeError`.

```
[NeMo W 2024-06-29 08:37:13 megatron_gpt_model:327] megatron_amp_O2 is enabled but transformer-engine is not.
Traceback (most recent call last):
  File "/workspace/src/3rdparty/NeMo/scripts/checkpoint_converters/convert_gpt_nemo_to_mcore.py", line 323, in <module>
    convert(
  File "/workspace/src/3rdparty/NeMo/scripts/checkpoint_converters/convert_gpt_nemo_to_mcore.py", line 244, in convert
    mcore_model = load_model(mcore_model, mcore_state_dict, ignore_if_missing=ignore_if_missing)
  File "/workspace/src/3rdparty/NeMo/scripts/checkpoint_converters/convert_gpt_nemo_to_mcore.py", line 172, in load_model
    raise RuntimeError(f"Unexpected key: {name} not in state_dict but in model.")
RuntimeError: Unexpected key: model.module.decoder.layers.0.input_layernorm.weight not in state_dict but in model.
```

**Expected behavior**

The script should write the converted checkpoint under the given `output_path`.

**Environment overview (please complete the following information)**

 - Environment location: Docker
 - Method of NeMo install: from source
   
    ```
    # Checked out at commit e33c8f7
    uv pip install --system --no-build-isolation --no-deps -e /workspace/src/3rdparty/Megatron-LM

    # Checked out at commit f1062b7
    uv pip install --system --no-build-isolation --no-deps -e "/workspace/src/3rdparty/NeMo[nlp]" && cd /workspace/src/3rdparty/NeMo/nemo/collections/nlp/data/language_modeling/megatron && make
    ```

 - If method of install is [Docker], provide `docker pull` & `docker run` commands used

**Environment details**

If NVIDIA docker image is used you don't need to specify these.
Otherwise, please provide:
- OS version: Ubuntu 22.04.4 LTS
- PyTorch version: 2.3.0a0+6ddf5cf85e.nv24.04
- Python version: Python 3.10.12

**Additional context**

Add any other context about the problem here.

GPU model: NVIDIA A100-SXM4-80GB
