Publishing error - IntegrityError: FOREIGN KEY constraint failed

[sentry]

It isn't clear if this caused publishing to fail. We should look into it

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Sentry Issue: STUDIO-GHS

IntegrityError: FOREIGN KEY constraint failed
  File "django/db/backends/utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "django/db/backends/sqlite3/base.py", line 423, in execute
    return Database.Cursor.execute(self, query, params)

IntegrityError: FOREIGN KEY constraint failed
(16 additional frame(s) were not displayed)
...
  File "contentcuration/viewsets/channel.py", line 464, in publish_from_changes
    self.publish(
  File "contentcuration/viewsets/channel.py", line 487, in publish
    channel = publish_channel(
  File "contentcuration/utils/publish.py", line 916, in publish_channel
    kolibri_temp_db = create_content_database(channel, force, user_id, force_exercises, progress_tracker=progress_tracker)
  File "contentcuration/utils/publish.py", line 145, in create_content_database
    kolibri_channel = map_channel_to_kolibri_channel(channel)
  File "contentcuration/utils/publish.py", line 730, in map_channel_to_kolibri_channel
    kolibri_channel = kolibrimodels.ChannelMetadata.objects.create(

[rtibbles]

This is very confusing - I checked the channel in question, and it has been successfully published 5 days ago.

However, looking at the code, I think this most likely is caused by publishing a channel that is either completely empty or only contains topics, and no resources.

[rtibbles]

Fixed in #4231