nautechsystems/nautilus_trader · error

debug_traceTransaction request failed

Error message

debug_traceTransaction request failed

What it means

`probe_call_trace` maps any transport error from its test `debug_traceTransaction` request that is not a rejected redirect to this generic "request failed" error, re-wrapping the underlying `BlockchainRpcClientError`. It signals the probe could not complete a successful HTTP exchange, so the endpoint's callTracer support could not be verified.

Source

Thrown at crates/adapters/blockchain/src/rpc/http.rs:827

                {
                    "tracer": "callTracer",
                    "tracerConfig": {
                        "onlyTopCall": false,
                        "withLog": false,
                    },
                }
            ],
        });
        let bytes = self
            .send_rpc_request(request, Some(EXECUTION_RPC_TIMEOUT_SECS))
            .await
            .map_err(|e| match e {
                BlockchainRpcClientError::ClientError(message)
                    if message.contains("redirect response rejected") =>
                {
                    anyhow::anyhow!("debug_traceTransaction redirect rejected")
                }
                _ => anyhow::anyhow!("debug_traceTransaction request failed"),
            })?;
        let parsed =
            serde_json::from_slice::<RpcNodeHttpResponse<serde_json::Value>>(bytes.as_ref())
                .map_err(|_| anyhow::anyhow!("Failed to parse debug_traceTransaction response"))?;
        if parsed.jsonrpc.is_none()
            && let (Some(code), Some(_)) = (parsed.code, parsed.message)
        {
            return trace_probe_result(code);
        }

        if let Some(error) = parsed.error {
            return trace_probe_result(error.code);
        }
        anyhow::ensure!(
            parsed.result.is_some(),
            "debug_traceTransaction returned no result"
        );
        Ok(())

View on GitHub (pinned to 18893faf8b)

Solutions

1. Check node reachability: curl the endpoint with a trivial eth_chainId request
2. Confirm the `debug` API namespace is enabled (e.g. geth `--http.api ...,debug` or erigon trace namespace)
3. Look at the wrapped source error for the precise cause (timeout vs refused vs HTTP status)
4. Retry or move the probe/tracing to a dedicated trace-enabled node

Example fix

// before: debug namespace disabled -> probe request fails
// geth flags: --http.api eth,net
// after: enable debug/trace namespace
// geth flags: --http.api eth,net,debug
// erigon flags: --http.api eth,erigon,trace

async fn debug_api_available(url: &str) -> bool {
    // any successful debug_* round trip proves the namespace is enabled
    send_raw(url, json!({"jsonrpc":"2.0","method":"debug_traceTransaction","params":[known_tx_hash, {"tracer":"callTracer"}],"id":1}))
        .await.is_ok()
}

match client.probe_call_trace().await {
    Ok(()) => Ok(()),
    Err(e) if e.to_string().contains("request failed") => {
        log::warn!("callTracer probe failed; check node reachability and debug namespace: {e}");
        Err(anyhow!("tracing endpoint unusable: {e}"))
    }
    Err(e) => Err(e),
}

When it happens

Trigger: Any non-redirect transport failure during the probe: connection refused/timeout, DNS failure, TLS errors, HTTP 5xx from the node, or the client error message not containing "redirect response rejected".

Common situations: Node down or unreachable (firewall, wrong host/port); `debug_*` namespace disabled causing error responses; timeouts on slow nodes; TLS certificate problems.

Understand the failure class

Background: 'Something went wrong' / 'Request failed (500)' / 'HTTP error! status: 404' — what failed HTTP requests actually mean and how to find the real cause — this error's family across 28 libraries.

Related errors

• debug_traceTransaction returned no result
• Failed to parse debug_traceTransaction response
• eth_call RPC error {code}
• eth_call RPC error {}
• debug_traceTransaction RPC error {code}

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/2c2cb8dcd13437f1. Report an issue: GitHub.