No data on nielsr/CelebA-faces
https://huggingface.co/datasets/nielsr/CelebA-faces

<img width="1056" alt="Capture d’écran 2022-03-21 à 17 12 55" src="https://user-images.githubusercontent.com/1676121/159303539-b3495de4-4308-477a-a1bd-fb65ee598933.png">

reported by @NielsRogge 

Possibly because the dataset is still in the job queue (https://datasets-preview.huggingface.tech/queue - https://huggingface.co/proxy-datasets-preview/queue-dump-waiting-started).

We should improve the error message in that case
No data on nielsr/CelebA-faces: https://huggingface.co/datasets/nielsr/CelebA-faces

<img width="1056" alt="Capture d’écran 2022-03-21 à 17 12 55" src="https://user-images.githubusercontent.com/1676121/159303539-b3495de4-4308-477a-a1bd-fb65ee598933.png">

reported by @NielsRogge 

Possibly because the dataset is still in the job queue (https://datasets-preview.huggingface.tech/queue - https://huggingface.co/proxy-datasets-preview/queue-dump-waiting-started).

We should improve the error message in that case