nautechsystems/nautilus_trader · error

Missing data in collect event log

Error message

Missing data in collect event log

What it means

parse_collect_event_hypersync throws this when the Hypersync-decoded Collect event payload is None, so amount0/amount1 and position tick data cannot be assembled into a Collect event. The parser refuses to emit a collect event with missing monetary amounts because those are required domain values. It mirrors the guard pattern used by the other uniswap_v3 event parsers.

Source

Thrown at crates/adapters/blockchain/src/exchanges/parsing/uniswap_v3/collect.rs:117

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

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

    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. Confirm the source contract is the canonical Uniswap V3 NonfungiblePositionManager and the log data section is present and correctly sized.
2. Re-check the Hypersync event/ABI registration for Collect so decoding yields Some(decoded).
3. Filter out logs with empty data before calling the parser, logging them for investigation instead of failing the batch.
4. Align adapter and Hypersync client versions, then re-fetch the affected block range.

Example fix

// before
let event = parse_collect_event_hypersync(&log)?;
// after
if log.data.is_empty() {
    tracing::warn!(tx = ?log.transaction_hash, "collect log has no data; skipping");
    return Ok(None);
}
let event = parse_collect_event_hypersync(&log)?;

fn can_parse_collect(log: &Log) -> bool {
    log.data.len() >= 64 // amount0, amount1 words
}

fn has_decoded_collect(decoded: &Option<CollectDecoded>) -> bool {
    decoded.is_some()
}

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

When it happens

Trigger: Calling parse_collect_event_hypersync with a log whose decoded field is None — topic0 matched the Collect signature but the data section was missing/truncated or Hypersync could not decode it into the expected Collect struct.

Common situations: Indexing NonfungiblePositionManager logs where an ABI update changed the expected Collect layout; non-standard fork contracts emitting Collect-like topic0 with no data; partially indexed blocks from Hypersync during reorgs; stale test fixtures.

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 burn 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/b1399fae436388d3. Report an issue: GitHub.