Attribute type missing from model training artifacts from train.py

[ankile]

System Info

- `lerobot` version: 0.1.0
- Platform: Linux-6.8.0-58-generic-x86_64-with-glibc2.35
- Python version: 3.10.15
- Huggingface_hub version: 0.25.0
- Dataset version: 3.6.0
- Numpy version: 1.26.0
- PyTorch version (GPU?): 2.7.0+cu126 (True)
- Cuda version: 12060
- Using GPU in script?: Yes, NVIDIA GeForce RTX 4090

Information

• One of the scripts in the examples/ folder of LeRobot
• My own task or dataset (give details below)

Reproduction

When trying to run

policy = DiffusionPolicy.from_pretrained(pretrained_policy_path)

with the output of running the training script like so:

python lerobot/scripts/train.py \                                          
    --dataset.repo_id=ankile/franka-lift \
    --policy.type=diffusion \              
    --wandb.enable=true

I get an error draccus.utils.ParsingError: Expected a dict with a 'type' key for <class 'lerobot.configs.policies.PreTrainedConfig'>

I.e., why doesn't the training script store a config.json that's complete in this case?

Expected behavior

It seems to me that the output of the train.py script when run with one of the default training configs, would output checkpoint files that would allow me to load them without errors.