Process does not exit after https request with keepAlive enabled (now default in Node 19)

Version

v19.8.1

Platform

Linux Jake-Framework 6.2.7-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 18 Mar 2023 01:06:36 +0000 x86_64 GNU/Linux

Subsystem

https

What steps will reproduce the bug?

Run a script containing:

const https = require("https");
const url = "https://github.com/dprint/dprint/releases/download/0.35.3/dprint-x86_64-unknown-linux-gnu.zip";
https.get(url, { method: "HEAD" }, console.log);

This will hang.

How often does it reproduce? Is there a required condition?

100% of the time; downgrade to Node 18 and it no longer hangs.

What is the expected behavior? Why is that the expected behavior?

No hang. Run this:

const https = require("https");
const url = "https://github.com/dprint/dprint/releases/download/0.35.3/dprint-x86_64-unknown-linux-gnu.zip";
https.get(url, { method: "HEAD", agent: new https.Agent({ keepAlive: false }) }, console.log);

And it will succeed.

What do you see instead?

Hang; the request succeeds and the response is given, but the process never exits.

Additional information

This is a change I saw in the Node 19 release blog post; keep-alive is enabled by default now, but, it seems to cause a hang.

Start by running the provided https.get reproduction on Node v19.8.1 and compare it with the keepAlive:false variant and Node 18. Trace the https request and agent lifecycle to determine why a successful HEAD response keeps the process alive. Done means the default keep-alive behavior no longer leaves this process hanging, with coverage for the reported reproduction.