[BUG] fail to execute task harness|bbh:movie_recommendation|0

[colinzuo]

Describe the bug

LightevalTask:_get_docs_from_split expects self.formatter to return a doc, but default_prompts.py:bbh_movie_recommendation return [] for a certain line, which caused
error in line "doc.id = str(ix)"

To Reproduce

Run task:
harness|bbh:movie_recommendation|0

Expected behavior

should succeed.

Version info

0.11.0

[pskadasi]

facing same error, let me know if you have fixed it.