Using Unpic with Vercel

[artt]

Describe the bug
When using Vercel adapter (to supposedly use Vercel's image service), there's a problem loading the image.

First version

Link to repo | Link to site

// @ts-check
import { defineConfig } from 'astro/config';
import { imageService } from "@unpic/astro/service";
import vercel from "@astrojs/vercel";

export default defineConfig({
  image: {
    service: imageService(),
  },
  adapter: vercel({
    imageService: true,
  }),
});

In this version, the image shows up correctly. The img element shows up as

<img src="/_vercel/image?url=_astro%2Ftest.BTqkgR0v.png&amp;w=640&amp;q=100" alt="Test" inputtedwidth="600" width="600" height="398" loading="lazy" decoding="async">

There's no srcset. Interestingly, when I change w=XXX to values other than 640, Vercel shows 404.

Second version

Link to repo | Link to site

// @ts-check
import { defineConfig } from 'astro/config';
import { imageService } from "@unpic/astro/service";
import vercel from "@astrojs/vercel";

export default defineConfig({
  image: {
    service: imageService(),
  },
  adapter: vercel({
    // imageService: true,
  }),
});

In this version, the image doesn't show up. The img element shows up with various source set. The url parameter is prepended with %2F.

<img src="/_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=600&amp;q=75" srcset="/_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=600&amp;q=75 600w, /_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=640&amp;q=75 640w, /_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=750&amp;q=75 750w, /_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=828&amp;q=75 828w, /_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=960&amp;q=75 960w, /_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=1080&amp;q=75 1080w, /_vercel/image?url=%2F_astro%2Ftest.BTqkgR0v.png&amp;w=1200&amp;q=75 1200w" alt="Test" url="/_astro/test.BTqkgR0v.png" loading="lazy" decoding="async" sizes="(min-width: 600px) 600px, 100vw" style="object-fit:cover;max-width:600px;max-height:398px;aspect-ratio:1.5075376884422111;width:100%">

Interestingly, when I change Removing the %2F and setting w=640 shows the image just fine.

Question

Am I doing something wrong? If I want just static website with Vercel's CDN, what do I have to do? With Netlify, I can just add the adapter and everything works. Link to that