This seems to be caused by destructuring from Gio.ActionGroup.query_action() into an object's properties. Something like this:

let actor = new Clutter.Actor();

[widget.visible, widget.reactive] = actionGroup.query_action('action-name');

My best guess so far, is that this is related to the (out) parameters of Gio.ActionGroup.query_action(), which may not detail the ownership transfer well enough for GJS:

https://gitlab.gnome.org/GNOME/glib/blob/72ed39a8c2e85bd4ef679572cd4e63126506e364/gio/gactiongroup.c#L740-L747

/**
 * g_action_group_query_action:
 * @action_group: a #GActionGroup
 * @action_name: the name of an action in the group
 * @enabled: (out): if the action is presently enabled
 * @parameter_type: (out) (optional): the parameter type, or %NULL if none needed
 * @state_type: (out) (optional): the state type, or %NULL if stateless
 * @state_hint: (out) (optional): the state hint, or %NULL if none
 * @state: (out) (optional): the current state, or %NULL if stateless
 *
 * <snip>
 *
 * Returns: %TRUE if the action exists, else %FALSE
 */
gboolean
g_action_group_query_action (GActionGroup        *group,
                             const gchar         *action_name,
                             gboolean            *enabled,
                             const GVariantType **parameter_type,
                             const GVariantType **state_type,
                             GVariant           **state_hint,
                             GVariant           **state)
{
}