python error on restore

Both the server (where the command is run) and the client are at version 
2.2.2-1 on Debian 12:

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sudo rdiff-backup --api-version 201 restore 
/home/backup/host1/rdiff/var/log/mail.log /tmp/rdiff-restore/mail.log

NOTE:    Starting restore operation from source path 
/home/backup/host1//rdiff to destination path /tmp/rdiff-restore/mail.log
Traceback (most recent call last):
   File "/usr/bin/rdiff-backup", line 33, in <module>
     sys.exit(load_entry_point('rdiff-backup==2.2.2', 'console_scripts', 
'rdiff-backup')())
 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/rdiffbackup/run.py", line 37, in 
main
     sys.exit(main_run(sys.argv[1:]))
              ^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/rdiffbackup/run.py", line 105, 
in main_run
     ret_val |= conn_act.run()
                ^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/rdiffbackup/actions/restore.py", 
line 192, in run
     ret_code |= self._operate_restore()
                 ^^^^^^^^^^^^^^^^^^^^^^^
   File "/usr/lib/python3/dist-packages/rdiffbackup/actions/restore.py", 
line 216, in _operate_restore
     self.dir.apply(src_diff_iter)
   File 
"/usr/lib/python3/dist-packages/rdiffbackup/locations/directory.py", 
line 219, in apply
     return self._shadow.apply(self.base_dir, source_diff_iter)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File 
"/usr/lib/python3/dist-packages/rdiffbackup/locations/_dir_shadow.py", 
line 307, in apply
     ITR(diff.index, diff)
   File "/usr/lib/python3/dist-packages/rdiff_backup/rorpiter.py", line 
131, in __call__
     self.root_branch.start_process_directory(*args)
   File 
"/usr/lib/python3/dist-packages/rdiffbackup/locations/_dir_shadow.py", 
line 367, in start_process_directory
     self._set_dir_replacement(diff_rorp, base_rp)
   File 
"/usr/lib/python3/dist-packages/rdiffbackup/locations/_dir_shadow.py", 
line 440, in _set_dir_replacement
     rpath.copy_with_attribs(diff_rorp, self.dir_replacement)
   File "/usr/lib/python3/dist-packages/rdiff_backup/rpath.py", line 
1732, in copy_with_attribs
     copy_attribs(rpin, rpout)
   File "/usr/lib/python3/dist-packages/rdiff_backup/rpath.py", line 
1675, in copy_attribs
     rpout.chown(*map_owners.map_rpath_owner(rpin))
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File 
"/usr/lib/python3/dist-packages/rdiffbackup/locations/map/owners.py", 
line 51, in map_rpath_owner
     return (_user_map(uid, uname), _group_map(gid, gname))
             ^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not callable

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Why am I seeing this?

How do I silence:

"WARNING: this command line interface is deprecated and will disappear, 
start using the new one as described with '--new --help'."

otherwise?