[rudycelekli]

Problem

load_dataset(..., dataset_type="CustomDatasetPath") — a documented option (docstring: "CustomDatasetPath if you just want to pass the full path to a preprocessed dataset") — raises UnboundLocalError immediately:

elif dataset_type == "CustomDatasetPath":
    try:
        train_dataset = load_from_disk(f"{dataset_name}/raw")
    except:
        train_dataset = Dataset_.from_file(f"{dataset_name}/raw.arrow")
    ...
    train_dataset = CustomDataset(
        train_dataset, durations=durations, preprocessed_mel=preprocessed_mel, **mel_spec_kwargs
    )   # UnboundLocalError: preprocessed_mel

preprocessed_mel is only assigned inside the "CustomDataset" branch (as False/True depending on audio_type). In the CustomDatasetPath branch it's never set, so the whole option is dead — UnboundLocalError: cannot access local variable 'preprocessed_mel'.

Fix

This branch loads raw audio, so set preprocessed_mel = False before constructing CustomDataset.