configuration_utils.to_json_string() fails on WindowsPath

[vincedovy]

Describe the bug

Running the diffusion-models-class/unit2/finetune_model.py line 117 (save_pretrained) and 01_finetuning_and_guidance.ipynb crashes trying to convert a WindowsPath to JSON. This worked prior to an conda update (not sure which module update caused the problem.) I have diffusers 0.29.0 installed. Issue was in configuration_utils.py line 590, where it checks whether the value is a PosixPath. My temporary fix was to insert the following lines:
elif isinstance(value, WindowsPath):
value = str(value.as_posix())

Reproduction

https://github.com/huggingface/diffusion-models-class/unit2/finetune_model.py

python finetune_model.py --image_size 128 --batch_size 8 --num_epochs 16
--grad_accumulation_steps 2 --start_model "google/ddpm-celebahq-256"
--dataset_name "Norod78/Vintage-Faces-FFHQAligned" --wandb_project 'dm-finetune'
--log_samples_every 100 --save_model_every 1000 --model_save_name 'vintageface'

Logs

No response

System Info

Windows 11 with NVIDIA GeForce RTX 4080 laptop GPU.
Python 3.11.8
pytorch 2.3.0
pytorch-cuda 12.1
diffusers 0.29.0
transformers 4.41.2

Who can help?

@DN6 @yiyixuxu @sayakpaul

[sayakpaul]

Thanks for reporting this issue. Since you already know a workaround would you mind opening a PR?

[vincedovy]

No problem.