Bun does not understand "localhost" in fetch

[pdenapo]

What version of Bun is running?

1.0.8+2a405f691e80725fe0b97b93afd3b8cfed13fa5f

What platform is your computer?

Linux 6.1.0-12-amd64 x86_64 unknown

What steps can reproduce the bug?

Run the following code that creates a hello-world express sever whith and end
point and fetch it using "localhost".
(I'm using express 4.18.2)

    var express = require("express");
    
    var app = express();
    app.get("/api", function (req, res) {
      res.send("hola");
    });
    var server = app.listen(8000, "127.0.0.1");
    
    const url = "http://localhost:8000";
    
    async function make_request() {
      let response = await fetch(url + "/api");
      const text = await response.text();
      console.log(text);
      server.close();
    }
    
    make_request();

What is the expected behavior?

Under node it returns "hola".

What do you see instead?

ConnectionRefused: Unable to connect. Is the computer able to access the url?
path: "http://localhost:8000/api"

Additional information

If you change the line with the server url to

const url = "http://127.0.0.1:8000";

everything works in bun as expected!

[JeffreyATW]

This doesn't work on Node either. I get this in Node:

➜ npx ts-node test.ts
TypeError: fetch failed
    at Object.fetch (node:internal/deps/undici/undici:14152:11)
    at processTicksAndRejections (node:internal/process/task_queues:95:5) {
  cause: Error: connect ECONNREFUSED ::1:8000
      at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1494:16) {
    errno: -61,
    code: 'ECONNREFUSED',
    syscall: 'connect',
    address: '::1',
    port: 8000
  }
}

Works in both Bun and Node if you remove the "127.0.0.1" from the listen call.

[pdenapo]

Strange. Seems to be something related to the network configuration in my machine. I'm using node 20.9.0

cat /etc/networks gives

default 0.0.0.0
loopback 127.0.0.0
link-local 169.254.0.0

However, for some reason bun and node are resolving the host address in a different way!

[pdenapo]

My operative system is Debian 12

[Electroid]

We will fix this, duplicate of #1425