https://sentry.io/the-sio2-project/szkopul/issues/229869377/

{code}
IntegrityError: update or delete on table "programs_test" violates foreign key constraint "test_id_refs_id_4c930bac06ff6a23" on table "programs_testreport"
DETAIL: Key (id)=(451179) is still referenced from table "programs_testreport".

(2 additional frame(s) were not displayed)
...
  File "django/db/transaction.py", line 225, in __exit__
    connection.commit()
  File "django/db/backends/base/base.py", line 173, in commit
    self._commit()
  File "django/db/backends/base/base.py", line 142, in _commit
    return self.connection.commit()
  File "django/db/utils.py", line 98, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "django/db/backends/base/base.py", line 142, in _commit
    return self.connection.commit()

IntegrityError: update or delete on table "programs_test" violates foreign key constraint "test_id_refs_id_4c930bac06ff6a23" on table "programs_testreport"
DETAIL: Key (id)=(451179) is still referenced from table "programs_testreport".

{code}