Hmbown/CodeWhale · error

serialized lane exit receipt exceeds size bound

Error message

serialized lane exit receipt exceeds size bound

What it means

write_lane_exit_receipt serializes the LaneExitReceipt (lane id plus exit code) and refuses to write if the JSON exceeds MAX_EXIT_RECEIPT_BYTES. The receipt is a fixed-shape tiny document, so exceeding the bound signals an internal invariant violation rather than user input.

Solutions

1. Shorten/normalize lane_id so the serialized receipt fits the bound.
2. If LaneExitReceipt legitimately grew, raise MAX_EXIT_RECEIPT_BYTES in the source.
3. Audit where lane_id is generated and cap its length at creation.

Example fix

// before
let lane_id = format!("lane-{}", huge_user_string);
// after
let lane_id = format!("lane-{}", hash_or_truncated_id);

let encoded = serde_json::to_vec(&receipt)?;
assert!(encoded.len() as u64 <= MAX_EXIT_RECEIPT_BYTES);

// this indicates an invariant bug: log lane_id length and the bound, then report
if e.to_string().contains("exit receipt exceeds size bound") { log::error!("receipt overflow: lane_id len={}", lane_id.len()); }

When it happens

Trigger: run_lane_log_proxy writing an exit receipt whose serialized form exceeds MAX_EXIT_RECEIPT_BYTES — realistically only if lane_id is enormous or the struct/serializer changed.

Common situations: Lane ids built from unbounded user input; a code change adding fields to LaneExitReceipt without revisiting the byte bound.

Understand the failure class

Background: "File too large" / "file size exceeds limit" errors: why libraries cap file sizes and how to fix them — this error's family across 46 libraries.

Related errors

• lane exit receipt exceeds bytes
• active plugin registry is missing its pre-dotenv…
• bounded provider catalog cache exceeds its write limit
• bounded to model output cap
• bundle at is bytes; the limit is bytes

AI-assisted analysis of Hmbown/CodeWhale@73e0f67d83 (2026-09-22). Data as JSON: /api/errors/3c007f350d076273. Report an issue: GitHub.

Appendix: source

Thrown at crates/lane/src/runtime.rs:378

            bail!("invalid lane environment key {key:?}");
        }
    }
    Ok(environment)
}

fn write_lane_exit_receipt(
    receipt_path: &Path,
    receipt_tmp_path: &Path,
    lane_id: &str,
    exit_code: i32,
) -> Result<()> {
    let encoded = serde_json::to_vec(&LaneExitReceipt {
        lane_id: lane_id.to_string(),
        exit_code,
    })
    .context("serialize lane exit receipt")?;
    if encoded.len() as u64 > MAX_EXIT_RECEIPT_BYTES {
        bail!("serialized lane exit receipt exceeds size bound");
    }
    remove_file_if_present(receipt_tmp_path)?;
    let mut options = OpenOptions::new();
    options.create_new(true).write(true);
    #[cfg(unix)]
    {
        use std::os::unix::fs::OpenOptionsExt;
        options.mode(0o600);
    }
    let result = (|| {
        let mut file = options
            .open(receipt_tmp_path)
            .with_context(|| format!("create {}", receipt_tmp_path.display()))?;
        file.write_all(&encoded)
            .with_context(|| format!("write {}", receipt_tmp_path.display()))?;
        file.sync_all()
            .with_context(|| format!("sync {}", receipt_tmp_path.display()))?;
        fs::rename(receipt_tmp_path, receipt_path)

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