deno: Used port is not freed when using Deno.run with --watch

When running this code

Deno.serve(() => {}, { port: x })

with this command

deno run -A --unstable --watch script.ts

I get this error everytime i make a change and have to kill the script (ctrl + c) and run it again.

Watcher File change detected! Restarting!
error: Uncaught (in promise) AddrInUse: Address already in use (os error 98)
Watcher Process finished. Restarting on file change...

deno 1.26.1 (release, x86_64-unknown-linux-gnu) Linux Fedora 37

About this issue

Original URL
State: closed
Created 2 years ago
Reactions: 3
Comments: 19 (1 by maintainers)

Commits related to this issue

fix(ext/flash): graceful server startup/shutdown (#16383) Fixes https://github.com/denoland/deno/issues/16267 Co-authored-by: Yusuke Tanaka <yusuktan@maguro.dev> — committed to denoland/deno by littledivy 2 years ago
fix(ext/flash): graceful server startup/shutdown (#16383) Fixes https://github.com/denoland/deno/issues/16267 Co-authored-by: Yusuke Tanaka <yusuktan@maguro.dev> — committed to bartlomieju/deno by littledivy 2 years ago

Most upvoted comments

You can get around this by adding an AbortController (which might be a good idea in general):

const abortController = new AbortController();

serve(myRequestHandler, {
  signal: abortController.signal,
  port: 8080,
});

globalThis.addEventListener("unload", () => abortController.abort());

lunsdorf on Mar 16, 2023

Yeah this isn’t fixed on 1.31.3 for the built-in Deno.serve.

$ deno --version
deno 1.31.3 (release, aarch64-apple-darwin)
v8 11.0.226.19
typescript 4.9.4

$ deno run --unstable --watch --allow-net mod.ts
Watcher Process started.
Listening on http://127.0.0.1:9000/
Watcher File change detected! Restarting!
error: Uncaught (in promise) AddrInUse: Address already in use (os error 48)

// mod.ts
Deno.serve(() => new Response("hi"));

oliverjam on Mar 17, 2023

Could this issue be re-opened? The problem is still present for me with deno 1.30.3 (release, aarch64-apple-darwin). It looks like there was some back-and-forth with reverted PRs—did a fix ever get merged and released?

oliverjam on Feb 21, 2023

This problem is happening in 1.31.2 as well in Windows computers (only arch we were able to reproduce)

lucis on Mar 10, 2023

Seeing this on 1.37.0 using Deno.serve.

It happens intermittently which perhaps suggests a race condition.

sjc5 on Sep 25, 2023

Fixed by https://github.com/denoland/deno/pull/18568

bartlomieju on Apr 3, 2023

sant123 on Mar 17, 2023

Issue seems to be fixed at deno 1.31.3 without needing the above workaround

qgates on Mar 16, 2023