nautechsystems/nautilus_trader · error

Missing data in burn event log

Error message

Missing data in burn event log

What it means

parse_burn_event_hypersync in the blockchain adapter's uniswap_v3 parsing module throws this when the Hypersync-decoded Burn event data is absent (the decoded payload is None), so the mandatory fields (amount, amount0, amount1, ticks) cannot be constructed. The library treats a burn log without decodable data as unusable rather than emitting a partial event. It is a data-integrity guard on the on-chain log ingestion path.

Source

Thrown at crates/adapters/blockchain/src/exchanges/parsing/uniswap_v3/burn.rs:114

                .as_ref(),
        );
        let pool_identifier = PoolIdentifier::Address(Ustr::from(&pool_address.to_string()));
        Ok(BurnEvent::new(
            dex,
            pool_identifier,
            extract_block_number(log)?,
            extract_transaction_hash(log)?,
            extract_transaction_index(log)?,
            extract_log_index(log)?,
            owner,
            tick_lower,
            tick_upper,
            decoded.amount,
            decoded.amount0,
            decoded.amount1,
        ))
    } else {
        Err(anyhow::anyhow!("Missing data in burn event log"))
    }
}

/// Parses a burn event from an RPC log.
///
/// # Errors
///
/// Returns an error if the log parsing fails or if the event data is invalid.
pub fn parse_burn_event_rpc(dex: SharedDex, log: &RpcLog) -> anyhow::Result<BurnEvent> {
    rpc_log::validate_event_signature(log, BURN_EVENT_SIGNATURE_HASH, "Burn")?;

    let owner = rpc_log::extract_address_from_topic(log, 1, "owner")?;

    // Extract int24 tickLower from topic2 (stored as a 32-byte padded value)
    let tick_lower_bytes = rpc_log::extract_topic_bytes(log, 2)?;
    let tick_lower = i32::from_be_bytes(tick_lower_bytes[28..32].try_into()?);

    // Extract int24 tickUpper from topic3 (stored as a 32-byte padded value)

View on GitHub (pinned to 18893faf8b)

Solutions

1. Check that the log actually comes from a canonical Uniswap V3 pool and has a non-empty data field (data.len() >= expected 32-byte words for the Burn event).
2. Verify the Hypersync query/ABI registration for the Burn event so the decoder produces Some(decoded); re-sync or re-fetch the log if decoding failed.
3. Inspect the raw log: if topic0 is the Burn signature but data is empty, the source contract is non-conforming — filter it out upstream.
4. Update the adapter/Hypersync client versions if decoding regressed after a dependency bump, then re-run the ingestion.

Example fix

// before
let decoded = decode_burn(log); // may be None
// after
if log.data.is_empty() {
    tracing::warn!(tx = ?log.transaction_hash, "skipping burn log with empty data");
    return Ok(None); // or filter before calling parse_burn_event_hypersync
}
let event = parse_burn_event_hypersync(&log)?;

fn can_parse_burn(log: &Log) -> bool {
    log.data.len() >= 96 // amount, amount0, amount1 words
}

fn has_decoded_burn(decoded: &Option<BurnDecoded>) -> bool {
    decoded.is_some()
}

match parse_burn_event_hypersync(&log) {
    Ok(event) => handle(event),
    Err(e) if e.to_string().contains("Missing data in burn event log") => {
        tracing::warn!("skipping malformed burn log");
    }
    Err(e) => return Err(e),
}

When it happens

Trigger: Calling parse_burn_event_hypersync with a Hypersync log whose decoded data field is None — e.g. the log's topic0 matched the Burn signature but the data section was absent, truncated, or Hypersync failed to decode it into the expected Burn struct.

Common situations: Ingesting logs from a malformed or non-standard contract that emits a Burn-shaped topic0 without conforming data; Hypersync ABI registration drift after a Uniswap V3 contract upgrade; querying a block range that includes partially indexed logs; copy-pasting a log from another DEX into a test fixture.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• Missing data in collect event log
• Missing data in initialize event log
• Missing data in mint event log
• Missing data in pool created event log
• Missing data in swap event log

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/27ab511016bd2941. Report an issue: GitHub.