[orm] build error with ?[]Child

[smichea]

Describe the bug

When having an entity that has a list of child, like

@[table: 'todolist']
pub struct TodoList {
    uuid string @[primary]
    todoitems ?[]TodoItem @[fkey:todolist]
    creationdate string @[default: 'CURRENT_TIMESTAMP';sql_type: 'TIMESTAMP']
    active ?bool 
    name string 
}

the build process throw the error

tmp/v_1000/mvtodolist.17075409489401821847.tmp.c:23730: error: field not found: len

which correspond to

Reproduction Steps

run the file

import db.pg

struct Member{
    id int @[primary]
    children ?[]Child @[fkey:parent_id]
}

struct Child{
	id int @[primary]
	parent_id int
}

fn main() {
	db := pg.connect(pg.Config{
		host: 'localhost' 
		user: 'meveo'
		password: 'meveo'
		dbname: 'meveo'
	}) or {
		println('failed to connect')
		println(err)
		return
	}
	sql db { create table Member } or {
		println(err)
	}
	new_member := Member{
		id: 1
		children: [Child{
			id: 1
			parent_id: 1
		}]
	}
	sql db { insert new_member into Member}!
}

Expected Behavior

either no error or an error at compilation time telling the ? should not be used with array of entities

Current Behavior

builder error :

$ v run testBug.v 
==================
/tmp/v_1000/testBug.6130289918847203090.tmp.c:18224: error: field not found: len
...
==================
(Use `v -cg` to print the entire error message)

builder error: 
==================
C error. This should never happen

Possible Solution

No response

Additional Information/Context

No response

V version

V 0.4.3 b5ba122

Environment details (OS name and version, etc.)

ubuntu 22.04.2 in wsl2 (win 11)

Note

You can use the 👍 reaction to increase the issue's priority for developers.

Please note that only the 👍 reaction to the issue itself counts as a vote.
Other reactions and those to comments will not be taken into account.