What causes "stop failed: {body}" in xai-org/grok-build?

Treat 'already dead' as success in cleanup code and ignore this error

stop failed: {body}

Error message

stop failed: {body}

What it means

stop() asks the session server to shut down. A non-2xx response is surfaced as this error with the server's body, typically because the session already exited or the port is stale.

Source

Thrown at crates/codegen/ptyctl-cli/src/commands/client.rs:211

    println!("{}", serde_json::to_string_pretty(&outcome)?);
    Ok(outcome
        .get("matched")
        .and_then(|m| m.as_bool())
        .unwrap_or(false))
}

/// Stop a session.
pub async fn stop(url: &str) -> Result<()> {
    let client = client_for(url)?;
    let resp = client
        .post(format!("{url}/control/stop"))
        .send()
        .await
        .context("failed to stop session")?;

    if !resp.status().is_success() {
        let body = resp.text().await.unwrap_or_default();
        anyhow::bail!("stop failed: {body}");
    }
    println!("Session stopped");
    Ok(())
}

View on GitHub (pinned to bc7f02eddd)

Solutions

Treat 'already dead' as success in cleanup code and ignore this error
Verify the session/port before stopping
Remove stale registry entries (`~/.ptyctl` registry dir) and re-run
Use --force on subsequent run to replace stale entries

Example fix

// before
client.stop(session).await?;
// after
if let Err(e) = client.stop(session).await {
    eprintln!("stop ignored: {e}"); // cleanup path: tolerate
}

Defensive patterns

Strategy: try-catch

Validate before calling

if let Ok(info) = registry::lookup_session(name) {
    if !server_alive(info.port).await { /* already dead: skip stop */ }
}

Try / catch

// cleanup paths should tolerate stop failures
if let Err(e) = client.stop(target).await {
    eprintln!("stop ignored during cleanup: {e}");
}

Prevention

Guard stop behind a liveness check to avoid double-stop noise
Idempotent cleanup: treat 'already stopped' as success
Run `ptyctl run --force` when registry entries may be stale

When it happens

Trigger: POST to the stop endpoint returning non-2xx — most often the session already died or the registry entry points to a dead/reused port.

Common situations: Cleanup in tests where the session already exited; double-stop from two cleanup paths; stale registry JSON after a crash.

Related errors

AI-assisted analysis of xai-org/grok-build@bc7f02eddd (2026-08-31). Data as JSON: /api/errors/cc25ece2611cc10e. Report an issue: GitHub.