Unexpected error with dynamic spawn before subtype declaration

[JoaoSamp]

data IFoo;

code/await/dynamic Foo_Action(var&/dynamic IFoo foo) -> none
do
end

code/await Spawn_Foo( var& IFoo foo ) -> none
do
	spawn/dynamic Foo_Action(&foo);
end

data IFoo.Foo2;

code/await/dynamic Foo_Action(var&/dynamic IFoo.Foo2 foo) -> none
do
	await 2s;
end

var IFoo.Foo2 foo2 = val IFoo.Foo2();
spawn Spawn_Foo(&foo2);
await FOREVER;