gvisor: rust http server cannot listen on port

I’m trying to run an http server written in Rust with this command:

docker run --init --runtime=runsc dgageot/rust

produces this error:

Starting web server v6
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ListenError { inner: Io(Os { code: 98, kind
: AddrInUse, message: "Address in use" }) }', libcore/result.rs:945:5
note: Run with `RUST_BACKTRACE=1` for a backtrace.
P9 server returned error. Gofer is shutting down. FD: 7, err: EOF

no matter which port I use.

Here’s the code for the container:

extern crate shio;

use shio::prelude::*;
use shio::http::{Method};

fn hello_world(_: Context) -> Response {
    Response::with("Hello from rust\n")
}

fn main() {
    println!("Starting web server v6");

    Shio::default()
        .route((Method::GET, "/", hello_world))
        .run(":8080")
        .unwrap();
}

and the cargo descriptor:

[package]
name = "run"
version = "0.1.0"
authors = ["David Gageot <david@gageot.net>"]

[dependencies]
shio = "0.3.0"

it’s built with this command to produce a statically linked binary.

cargo build --release --target x86_64-unknown-linux-musl