id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
31660	AttributeError is raised while grouping on reverse relation.	Tomasz Szymański	Mariusz Felisiak	"Aggregation by using StringAgg works in 3.0.6, doesn't in 3.0.7
{{{
qs = qs.annotate(
        filtered_attribute=models.FilteredRelation(
            relation_name=""attributes"",
        ),
        concatenated_values=models.Case(
            models.When(
                models.Q(filtered_attribute=None),
                then=models.Value(""""),
            ),
            default=StringAgg(
                models.F(""name""),
                delimiter="","",
            ),
            output_field=models.CharField(),
        ),
    )
}}}

the exception raised in 3.0.7:

{{{
'ManyToOneRel' object has no attribute 'select_format'
}}}

Possibly broken by:
https://github.com/django/django/pull/12913

Attatching a zipped project, steps to reproduce:
- `docker-compose build`
- `docker-compose docker-compose run web python manage.py migrate`
- `docker-compose up`
- Either access `localhost:8000/bug` or run the tests: `docker-compose run web python manage.py test`
----
"	Bug	closed	Database layer (models, ORM)	3.0	Release blocker	fixed		Mikail	Accepted	1	0	0	0	0	0