Episode 396 can't be loaded on its own: its metadata points to the wrong data file (lerobot#2401)
#2
by rs1g6r - opened
Hi! Episode 396 is the first episode in data/chunk-000/file-001.parquet, but its data/file_index in meta/episodes is 0, so its metadata names file-000.parquet. That's the file-boundary bug in LeRobot's v2.1 → v3.0 converter (huggingface/lerobot#2401, fixed since).
What it breaks, checked with LeRobot 0.6.1 from a fresh cache:
LeRobotDataset("unitreerobotics/G1_Dex3_ToastedBread_Dataset", episodes=[396])
# ValueError: Instruction "train" corresponds to no data!
LeRobotDataset("unitreerobotics/G1_Dex3_ToastedBread_Dataset", episodes=[395])
# loads its 782 frames
Loading a subset downloads only the files the metadata names, so episode 396's rows are never fetched. Loading the whole dataset works.
Fix: set episode 396's data/file_index to 1 (or re-convert with a current LeRobot).
Found with rdq, an open-source checker for robot datasets (rdq check <repo> reports it as meta.data_file). Happy to re-check after a fix.