`referenced in BY but not declared in USING` in group by off of backlink

[jackfischer]

• EdgeDB Version: 3.2 and 3.3
• EdgeDB CLI Version: 3.4.0+4d95a2c
• OS Version: macos 13

Steps to Reproduce:

1. Throws error (with helpful guidance) UnsupportedFeatureError: may not group by a field named id Hint: try 'using id_ := .id'

   group(
   select AuditLog.user
   ) by (.id);

2. Aliasing as recommended works as expected,

   group(
   select AuditLog.user {id_:=.id}
   ) by (.id_);

3. Add a backlink in the path,

   group(
   select ActivitySource.<context[is AuditLog].user {id_:=.id}
   ) by (id_);

   error: InvalidReferenceError: variable 'id_' referenced in BY but not declared in USING
   ┌─ <query>:3:7
   │
   3 │ ) by (id_);
   │       ^^^ error

Schema:

type User {}
type AuditLog {
    user: User;
    context: ActivitySource;
}
type ActivitySource {}

[raddevon]

I think this one is actually OK. You just need a leading dot on your by:

group(
  select ActivitySource.<context[is AuditLog].user {id_:=.id}
) by (.id_);

or if you define your alias in using instead, you can forego the leading dot:

group(
  select ActivitySource.<context[is AuditLog].user
) using id_ := .id by (id_);

Feel free to re-open if I've missed something here.

[jackfischer]

Ahhhhh I misinterpreted this as somehow an error coming out of postgres from a corrupt query. EdgeDB also has the concept of using.