Default fetch polyfill breaks ky-universal

Bug report

I use ky-universal, which is built on top of node-fetch. After upgrading to Next.js 9.4, it has started throwing "Only absolute URLs are supported" errors on the Node.js side, even though an absolute URL is set and it works on Next.js 9.3.x.

To Reproduce

1. Use ky-universal in a Next.js project to make a request on the server side.
2. Watch it throw a "Only absolute URLs are supported" error.

Expected behavior

Shouldn’t throw an error, and should work like it did in Next.js 9.3.x.

System information

• OS: macOS
• Version of Next.js: 9.4.0
• Version of Node.js: 14.1.0

Additional context

It looks like the default polyfill is interfering with the library somehow, but I can’t figure out what/how. Also, pasting from https://github.com/zeit/next.js/pull/12353#issuecomment-627064091 —

node-fetch has an upcoming v3 release (in beta now) that fixes a long-standing issue, and ky-universal is in the process of using it in their next release, which is vital when working with large API payloads.

Similar reports —

1. https://github.com/zeit/next.js/pull/12353#issuecomment-625114086
2. https://github.com/zeit/next.js/discussions/12732

[paambaati]

@timneutkens Thanks, I can confirm that this is fixed and ky-universal works fine on 9.4.1-canary.1.

[timneutkens]

Hey! Thanks for the report, I’ve fixed the issue here: #12804