ORM query with Count(Subquery(...)) produces invalid SQL with Django 3.0.

[Alex]

There is an ORM query in my app, which I wrote when Django 2.2 was used and it broke after migrating to 3.0:

    Targets.objects.filter(hgnc_sym=sym_list)
            .annotate(
                num_of_drugs=Count(
                    Subquery(Drug.objects.filter(id__in=OuterRef('drugs__id'),).distinct('id').values('id')),
                    distinct=True,
                )
            )

There are two models (Targets, Drug) with a M2M relation through targetdrug table. I am annotating each Targets record with count of related Drugs.
Django produces SQL queries that look almost the same except one brackets set.
Here is the SQL code produced by Django 2.2:

SELECT "targets"."hgnc_sym",
       COUNT(DISTINCT
               (SELECT DISTINCT ON (U0."id") U0."id"
                FROM "drug" U0
                WHERE U0."id" IN ("targetdrug"."drug_id"))) AS "num_of_drugs"
FROM "targets"
LEFT OUTER JOIN "targetdrug" ON ("targets"."id" = "targetdrug"."target_id")
WHERE "targets"."hgnc_sym" IN ('ABC')
GROUP BY "targets"."id";

and here is same SQL, produced by Django 3.0:

SELECT "targets"."hgnc_sym",
       COUNT(DISTINCT
               (SELECT DISTINCT ON (U0."id") U0."id"
                FROM "drug" U0
                WHERE U0."id" IN "targetdrug"."drug_id")) AS "num_of_drugs"
FROM "targets"
LEFT OUTER JOIN "targetdrug" ON ("targets"."id" = "targetdrug"."target_id")
WHERE "targets"."hgnc_sym" IN ('ABC')
GROUP BY "targets"."id";

The problem is that last SQL script misses brackets at line starting with WHERE U0."id" IN ....
Running that SQL results into the following error:

syntax error at or near ""targetdrug""
LINE 5:                 WHERE U0."id" IN "targetdrug"."drug_...

Postgres version:
PostgreSQL 11.4 (Debian 11.4-1.pgdg90+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516, 64-bit
Django version:
python -c 'import django; print(django.VERSION)'
(3, 0, 2, 'final', 0)

[Mariusz Felisiak]

Duplicate of #31135. Using __in lookup with OuterRef() is not supported, you should use Drug.objects.filter(id=OuterRef('drugs__id')) instead.