[MM3-users] New problem on new installation of Mailman

I am just about done with installing Mailman 3 on a new Debian 10 server and when I go to run ./mailman-post-update, I am running into the following error:

./mailman-post-update

• '[' False == False ']'
• mkdir -p /opt/mailman/mm/static
• /opt/mailman/mm/bin/django-admin collectstatic --clear --noinput --verbosity 0 Traceback (most recent call last): File "/opt/mailman/mm/venv/bin/django-admin", line 10, in <module> sys.exit(execute_from_command_line()) File "/opt/mailman/mm/venv/lib/python3.7/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line utility.execute() File "/opt/mailman/mm/venv/lib/python3.7/site-packages/django/core/management/__init__.py", line 377, in execute django.setup() File "/opt/mailman/mm/venv/lib/python3.7/site-packages/django/__init__.py", line 24, in setup apps.populate(settings.INSTALLED_APPS) File "/opt/mailman/mm/venv/lib/python3.7/site-packages/django/apps/registry.py", line 91, in populate app_config = AppConfig.create(entry) File "/opt/mailman/mm/venv/lib/python3.7/site-packages/django/apps/config.py", line 90, in create module = import_module(entry) File "/usr/lib/python3.7/importlib/__init__.py", line 127, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "<frozen importlib._bootstrap>", line 1006, in _gcd_import File "<frozen importlib._bootstrap>", line 983, in _find_and_load File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 677, in _load_unlocked File "<frozen importlib._bootstrap_external>", line 728, in exec_module File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed File "/opt/mailman/mm/venv/lib/python3.7/site-packages/haystack/__init__.py", line 11, in <module> from haystack.utils import loading File "/opt/mailman/mm/venv/lib/python3.7/site-packages/haystack/utils/__init__.py", line 9, in <module> from django.utils import six ImportError: cannot import name 'six' from 'django.utils' (/opt/mailman/mm/venv/lib/python3.7/site-packages/django/utils/__init__.py)

I assume it has something to do with Haystack.

Suggestions for a fix?

Thanks, Brian