Why does optional prop cause a wasm error?

[dominictobias]

Wondering if I'm doing something obviously wrong? Using 0.5 alpha.0

Even if I don't use the optional props in rsx it errors as soon as I add one to the struct:

#![allow(non_snake_case)]
use dioxus::prelude::*;

#[derive(PartialEq, Props, Clone)]
pub struct ButtonProps {
    #[props(extends = GlobalAttributes)]
    attributes: Vec<Attribute>,
    left_icon: Option<Element>,
    right_icon: Option<Element>,
    children: Element,
}

pub fn Button(props: ButtonProps) -> Element {
    rsx! {
        button { ..props.attributes, {props.left_icon}, {props.children}, {props.right_icon} }
    }
}

localhost/:1 Uncaught (in promise) LinkError: WebAssembly.instantiate(): Import #203 module="wbg" function="__wbindgen_closure_wrapper3227": function import requires a callable

It's something to do with combining with attributes