addCustomAttribute not working on MetaLinks

[0xTim]

When using addCustomAttribute on a MetaLink, e.g.

MetaLink(href: "https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css", rel: "stylesheet")
    .addCustomAttribute(name: "integrity", value: "sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH")
    .addCustomAttribute(name: "crossorigin", value: "anonymous")

I would expect the output to be

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH" crossorigin="anonymous">

However, it is only generating

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet">

The same code with a Script for example works:

Script(file: "https://cdn.jsdelivr.net/npm/@popperjs/[email protected]/dist/umd/popper.min.js")
    .addCustomAttribute(name: "integrity", value: "sha384-I7E8VVD/ismYTF4hNIPjVp/Zjvgyol6VFvRkX/vR+Vc4jQkC+hVqc2pM8ODewa9r")
    .addCustomAttribute(name: "crossorigin", value: "anonymous")

Generates correctly:

<script integrity="sha384-0pUGZvbkm6XF6gxjEnlmuGrJXVbNuzT9qBBavbLwCsOGabYfZo0T0to5eqruptLy" crossorigin="anonymous" src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js"></script>