openai/codex · error · std::io::Error

message too large: {len}

Error message

message too large: {len}

What it means

Error "message too large: {len}" thrown in openai/codex.

Source

Thrown at codex-rs/shell-escalation/src/unix/socket.rs:202

    } else {
        MsgHdr::new().with_buffers(&payload).with_control(&control)
    };
    let written = socket.sendmsg(&msg, 0)?;
    if written != data.len() {
        return Err(std::io::Error::new(
            std::io::ErrorKind::WriteZero,
            format!(
                "short datagram write: wrote {written} bytes out of {}",
                data.len()
            ),
        ));
    }
    Ok(())
}

fn encode_length(len: usize) -> std::io::Result<[u8; LENGTH_PREFIX_SIZE]> {
    let len_u32 = u32::try_from(len).map_err(|_| {
        std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("message too large: {len}"),
        )
    })?;
    Ok(len_u32.to_le_bytes())
}

fn make_control_message(fds: &[OwnedFd]) -> std::io::Result<Vec<u8>> {
    if fds.len() > MAX_FDS_PER_MESSAGE {
        Err(std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("too many fds: {}", fds.len()),
        ))
    } else if fds.is_empty() {
        Ok(Vec::new())
    } else {
        let mut control = vec![0u8; control_space_for_fds(fds.len())];
        unsafe {

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/shell-escalation/src/unix/socket.rs:202 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/2c23ab3ba0254059. Report an issue: GitHub.