local variable 'id_length' referenced before assignment

[xyin0918]

Hi,
Thank you for this tutorial! It is very useful and I have almost done. But I was trying to merge the data in the step: adata = scv.utils.merge(adata, ldata). I got this error:
UnboundLocalError Traceback (most recent call last)
Cell In[5], line 1
----> 1 adata = scv.utils.merge(adata, ldata)

File ~/.local/lib/python3.9/site-packages/scvelo/core/_anndata.py:526, in merge(adata, ldata, copy, **kwargs)
524 if "id_length" in kwargs:
525 id_length = kwargs.get("id_length")
--> 526 clean_obs_names(adata, id_length=id_length)
527 clean_obs_names(ldata, id_length=id_length)
528 common_obs = adata.obs_names.intersection(ldata.obs_names)

UnboundLocalError: local variable 'id_length' referenced before assignment
Do you have any idea why this error happens? Thank u very much!