[TOPF] Cron <mailman@mailman> django-admin runjobs minutely --pythonpath /srv/mailman --settings settings

[ERROR/MainProcess] Failed indexing 1 - 1000 (retry 5/5): unsupported pickle protocol: 4 (pid 15482): unsupported pickle protocol: 4 Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/haystack/management/commands/update_index.py", line 84, in do_update backend.update(index, current_qs, commit=commit) File "/usr/local/lib/python2.7/dist-packages/haystack/backends/whoosh_backend.py", line 178, in update self.setup() File "/usr/local/lib/python2.7/dist-packages/haystack/backends/whoosh_backend.py", line 126, in setup self.index = self.storage.open_index(schema=self.schema) File "/usr/lib/python2.7/dist-packages/whoosh/filedb/filestore.py", line 176, in open_index return indexclass(self, schema=schema, indexname=indexname) File "/usr/lib/python2.7/dist-packages/whoosh/index.py", line 421, in __init__ TOC.read(self.storage, self.indexname, schema=self._schema) File "/usr/lib/python2.7/dist-packages/whoosh/index.py", line 664, in read segments = stream.read_pickle() File "/usr/lib/python2.7/dist-packages/whoosh/filedb/structfile.py", line 245, in read_pickle return load_pickle(self.file) ValueError: unsupported pickle protocol: 4