zulip: Errors importing from Stride (not Hipchat) using the Stride export tool

Trying out Zulip for the first time and the experience has been really nice and smooth so far.

One issue when giving the Stride import a try (obviously not exactly hipchat but should be similar)

Decrypted with the following command (this varies slightly from the official way to decrypt the hipchat export):

openssl enc -md md5 -aes-256-cbc -salt -d -in stride-abcdefg.tar.gz.aes -out stride.tar.gz -k secret

Then imported:

./manage.py convert_hipchat_data ~/stride.tar.gz --output converted_hipchat_data

Traceback follows:

Converting Data ...
2018-11-09 20:37:20.805 INFO [] input data was untarred to /home/zulip/stride
Traceback (most recent call last):
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 880, in get_queryset
    return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
AttributeError: 'UserProfile' object has no attribute '_prefetched_objects_cache'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "./manage.py", line 46, in <module>
    execute_from_command_line(sys.argv)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/core/management/__init__.py", line 356, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/core/management/base.py", line 283, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/core/management/base.py", line 330, in execute
    output = self.handle(*args, **options)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zerver/management/commands/convert_hipchat_data.py", line 77, in handle
    masking_content=options.get('masking_content', False),
  File "/home/zulip/deployments/2018-11-09-14-14-01/zerver/data_import/hipchat.py", line 696, in do_convert_data
    realm_id=realm_id,
  File "/home/zulip/deployments/2018-11-09-14-14-01/zerver/data_import/hipchat.py", line 151, in convert_user_data
    user = process(raw_item)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zerver/data_import/hipchat.py", line 147, in process
    timezone=timezone,
  File "/home/zulip/deployments/2018-11-09-14-14-01/zerver/data_import/import_util.py", line 60, in build_user_profile
    dct = model_to_dict(obj)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/forms/models.py", line 97, in model_to_dict
    data[f.name] = f.value_from_object(instance)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/fields/related.py", line 1683, in value_from_object
    return getattr(obj, self.attname).all()
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/manager.py", line 160, in all
    return self.get_queryset()
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 883, in get_queryset
    return self._apply_rel_filters(queryset)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 870, in _apply_rel_filters
    return queryset._next_is_sticky().filter(**self.core_filters)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/query.py", line 787, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/query.py", line 805, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1250, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1276, in _add_q
    allow_joins=allow_joins, split_subq=split_subq,
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1210, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1104, in build_lookup
    return final_lookup(lhs, rhs)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/lookups.py", line 24, in __init__
    self.rhs = self.get_prep_lookup()
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/lookups.py", line 74, in get_prep_lookup
    return self.lhs.output_field.get_prep_value(self.rhs)
  File "/home/zulip/deployments/2018-11-09-14-14-01/zulip-py3-venv/lib/python3.6/site-packages/django/db/models/fields/__init__.py", line 966, in get_prep_value
    return int(value)
ValueError: invalid literal for int() with base 10: '557058:975d0e3c-f10d-42e9-9578-abcdef1234'