deno: Deno.listen should throw on same port

const listener1 = Deno.listen({
  port: 4505,
  hostname: "0.0.0.0",
  transport: "tcp",
});

console.log(listener1.addr);

const listener2 = Deno.listen({
  port: 4505,
  hostname: "0.0.0.0",
  transport: "tcp",
});

console.log(listener2.addr);

Expected behavior

The code should throw according with docs.

Current behavior

The constant listener2 will have assigned a random port.

Also this test is hanging because of this https://github.com/denoland/deno_std/blob/main/http/server_test.ts#L1280

About this issue

Original URL
State: closed
Created a year ago
Comments: 17 (7 by maintainers)

Most upvoted comments

That’s a nice discovery @sant123. The kernel version I tried was 5.17.5-300.fc36.x86_64. I discovered that there is a regression report for Linux kernel which can be found at: https://lore.kernel.org/netdev/CAFsF8vJ3wS-Yoy9tNZD2ZESevGenvYKqieD4F8+UztRsrJ=png@mail.gmail.com/T/ According to this, 6.0.16 to 6.0.18 suffers from this problem, so it’s most likely that you ran into this kernel regression.

I’m going to close this issue since it’s turned out that this is actually not a issue with Deno. If you have another question or something, feel free to ask 😃

magurotuna on Jan 16, 2023

I gave it another try to run Fedora with vagrant (i.e. virtualbox) instead of docker, and got AddrInUse again. What you are seeing is really weird…

magurotuna on Jan 14, 2023