InternalServerError: invalid request for non-scalar path when using a subtype

[Gobot1234]

• EdgeDB Version: v7 nightly

Steps to Reproduce:

with reps := (select users::Rep filter .username in {'mea21jbh', 'coa20gcs'}),
carrie := (select assert_single(users::Rep filter .first_name = "Carrie")),
for user in reps union (
    update user
    set {
        training += (
            select .training {
                @created_at := @created_at,
                @infraction := @infraction,
                @in_person_created_at := datetime_of_statement(),
                @in_person_signed_off_by := assert_exists(carrie.id),
            }
            filter .id = <uuid>$training_id
        )
    }
)

Raises

InternalServerError: invalid request for non-scalar path (__derived__::user@w~3) iterator

Whereas changing users::Rep to users::User makes the error disappear

with reps := (select users::Users filter .username in {'mea21jbh', 'coa20gcs'}),
carrie := (select assert_single(users::Rep filter .first_name = "Carrie")),
for user in reps union (
    update user
    set {
        training += (
            select .training {
                @created_at := @created_at,
                @infraction := @infraction,
                @in_person_created_at := datetime_of_statement(),
                @in_person_signed_off_by := assert_exists(carrie.id),
            }
            filter .id = <uuid>$training_id
        )
    }
)

Schema:

type User;
type Rep extending User;