Function passing not working? #67

I'm trying to do something sort of complicated on my site (basically work around #66) using the function passing capability, but it doesn't seem to be working for me. I simplified it down to a minimal form. I have this global data file cachetest.js:

import Fetch from "@11ty/eleventy-fetch"

export default async function() {
    return await Fetch(async () => {
        console.log("Cache miss")
        return {
            foo: "bar"
        }
    }, {
        requestId: "cachetest",
        duration: "1h"
    })
}

Each time I run it logs "Cache miss" to the shell output. Never does it seem to write anything to .cache. Have I done something wrong here?