create_tag_synonyms is broken

[sebastian-philipp]

(py3.6) ➜  testproject git:(fix-tag-editor) ✗ DJANGO_SETTINGS_MODULE=testproject.settings  python manage.py create_tag_synonyms --from tag1 --to tag2
b"WARNING!!! You are using a 'locmem' (local memory) caching backend,\nwhich is OK for a low volume site running on a single-process server.\nFor a multi-process configuration it is neccessary to have a production\ncache system, such as redis or memcached.\n\nWith local memory caching and multi-process setup you might intermittently\nsee outdated content on your site.\n"
System check identified some issues:

WARNINGS:
?: (urls.W001) Your URL pattern '^robots.txt$' uses include with a route ending with a '$'. Remove the dollar from the route to avoid problems including URLs.
django_authopenid.UserPasswordQueue.user: (fields.W342) Setting unique=True on a ForeignKey has the same effect as using a OneToOneField.
        HINT: ForeignKey(unique=True) is usually better served by a OneToOneField.
group_messaging.SenderList.recipient: (fields.W342) Setting unique=True on a ForeignKey has the same effect as using a OneToOneField.
        HINT: ForeignKey(unique=True) is usually better served by a OneToOneField.

You have not provided user id for the moderator
who to assign as the performer this operation, the default moderator is
admin, id=1. Will that work?
type yes/no: yes

You have not provided user id for the moderator
who to assign as the performer this operation, the default moderator is
admin, id=1. Will that work?
type yes/no: yes
4 questions match:
* tagged questiontagged question
* test tag1test tag1test tag1test tag1test tag1
* tag1adfsfsdfsdfgdsfg
* uhhuhhuhhuhh

Rename tags tag1 --> tag2?
type yes/no: yes
Processing:Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/base.py", line 323, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/askbot/management/commands/create_tag_synonyms.py", line 142, in handle
    management.call_command('rename_tags', *args, **options)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/__init__.py", line 148, in call_command
    return command.execute(*args, **defaults)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/askbot/management/commands/rename_tags.py", line 170, in handle
    management.call_command('rename_tags_id', *args, **options)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/__init__.py", line 148, in call_command
    return command.execute(*args, **defaults)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/core/management/base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/askbot/management/commands/rename_tags_id.py", line 184, in handle
    question = question._question_post(),
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/askbot/models/question.py", line 651, in _question_post
    self._question_cache = Post.objects.get(post_type='question', thread=self)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/db/models/manager.py", line 82, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/sebastian/Repos/askbot-devel/.tox/py3.6/lib/python3.6/site-packages/django/db/models/query.py", line 408, in get
    self.model._meta.object_name
askbot.models.post.DoesNotExist: Post matching query does not exist.