At compiling valac produces the following error:

valaNonGobjectClass.vala:13.3-13.9: error: duplicating Node instance, use weak variable or explicitly invoke copy method
		Node<G> node = new Node<G>();
		^^^^^^^

** (valac:23238): CRITICAL **: vala_ccode_assignment_new: assertion `VALA_IS_CCODE_EXPRESSION (r)' failed

** (valac:23238): CRITICAL **: vala_ccode_comma_expression_append_expression: assertion `VALA_IS_CCODE_EXPRESSION (expr)' failed

The code:

using GLib;

public class SomeClass<G> : Object {

	[Compact]
	private class Node<G> {
		public Node<G> next = null;
	}

	Node<G> first = new Node<G>();

	public void create() {
		Node<G> node = new Node<G>();

		node.next = #first;
		first = node;
	}

}

public static void main(string[] args) {
	var i = new SomeClass<int>();
	i.create();
}

The problem is at line: "first = node;" in create method as it node doesn't transfer ownership to first, but as vala reports the error being with ownership transfer at "Node<G> node = new Node<G>();"