The 0010_auto_20200508_1851 migration doesn't seem to be reversable

[Lorac]

After I imported the data, I wanted to restart fresh, so I tried to migrate backward.

  Unapplying cities_light.0010_auto_20200508_1851...Traceback (most recent call last):
  File ".../lib/python3.11/site-packages/django/db/backends/utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
psycopg2.errors.UniqueViolation: could not create unique index "cities_light_city_region_id_name_29b81cd4_uniq"
DETAIL:  Key (region_id, name)=(57, Neston) is duplicated.

Since I wanted to restart fresh, I deleted the offending cities. But I got more from the slug, too:

  Unapplying cities_light.0010_auto_20200508_1851...Traceback (most recent call last):
  File ".../.venv/lib/python3.11/site-packages/django/db/backends/utils.py", line 89, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
psycopg2.errors.UniqueViolation: could not create unique index "cities_light_city_region_id_slug_dc18c213_uniq"
DETAIL:  Key (region_id, slug)=(57, ashford) is duplicated.

Since there is duplication, It is impossible to revert to the old unique_together key which is : 'unique_together': set([('region', 'name'), ('region', 'slug')]),

[marianoeramirez]

Thats right. You should delete the duplicate row manually before revert.

[Lorac]

Would it be possible to squash all the migrations together?

[marianoeramirez]

It's not recommended because of this public library is being used across multiple servers in different situations. There are on other status and we want to allow them to move to a new version of the library without any issues.