openai/codex · error · std::io::Error

could not resolve to any address

Error message

could not resolve to any address

What it means

Error "could not resolve to any address" thrown in openai/codex.

Source

Thrown at codex-rs/websocket-client/src/dialer.rs:214

    let addresses = tokio::net::lookup_host(address).await?.collect::<Vec<_>>();
    let stream = connect_happy_eyeballs(addresses, TcpStream::connect).await?;
    if tcp_nodelay == TcpNodelay::Enabled {
        stream.set_nodelay(/*nodelay*/ true)?;
    }
    Ok(stream)
}

async fn connect_happy_eyeballs<T, F, Fut>(
    addresses: Vec<SocketAddr>,
    mut connect: F,
) -> io::Result<T>
where
    F: FnMut(SocketAddr) -> Fut,
    Fut: Future<Output = io::Result<T>>,
{
    let mut addresses = addresses.into_iter();
    let Some(first_address) = addresses.next() else {
        return Err(io::Error::new(
            io::ErrorKind::InvalidInput,
            "could not resolve to any address",
        ));
    };

    let first_is_ipv4 = first_address.is_ipv4();
    let mut preferred = VecDeque::new();
    let mut alternate = VecDeque::new();
    for address in addresses {
        if address.is_ipv4() == first_is_ipv4 {
            preferred.push_back(address);
        } else {
            alternate.push_back(address);
        }
    }

    let mut addresses = VecDeque::new();
    while !preferred.is_empty() || !alternate.is_empty() {

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/websocket-client/src/dialer.rs:214 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/fa1a1eb2e99944f7. Report an issue: GitHub.