[MM3-users] ModuleNotFoundError: No module named 'xapian_backend'

I had a working mailman3, tore it down, switched to PostgreSQL (from MySQL), and now everything is working, except:

mailman-web update_index

and

mailman-web update_index_one_list

They fail with:

ModuleNotFoundError: No module named 'xapian_backend'

I rebuilt and re-installed xapian:

(venv) mailman@mail:~$ echo $XAPIAN_VERSION 1.4.25

(venv) mailman@mail:~$ pip list | grep -i xapian xapian 1.4.25

Any ideas?

Thanks!

rb