fetch in next.83 errors with: Cannot read property 'split' of undefined

[vinkodlak]

i get this error:

500
Cannot read property 'split' of undefined

TypeError: Cannot read property 'split' of undefined
at parse_body (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:1330:60)
at ssr (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:1448:9)
at fetch (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:697:30)
at load (index.svelte:3:27)
at load_node (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:784:30)
at respond (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:1006:21)
at async render_page (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:1154:20)
at async render (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:1467:10)
at async ssr (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/ssr.js:1454:10)
at async Immediate. (file:///Users/vinkov/svelte/novo/node_modules/@sveltejs/kit/dist/chunks/index.js:3297:23)

with this simple code:

<script context="module">
  export async function load({fetch}) {
    const res = await fetch('/server', {
      method: 'POST',
      body: {}
    })

    const { name } = await res.json()

    return {
      props: {
        name
      }
    }
  }
</script>
<script>
  export let name
</script>

<h1>{name}, Welcome to SvelteKit</h1>
<p>Visit <a href="https://kit.svelte.dev">kit.svelte.dev</a> to read the documentation</p>

when body is null or '' is works fine
if i put JSON.stringify({...}) there is same error

server.js is simple as this:

export async function post() {
  return {
    body: {
      name: 'My Name'
    }
  }
}

[vinkodlak]

reverting to 80 works, breaks with 81

[Conduitry]

Duplicate of #1127.