linera-io/linera-protocol · critical

invalid block export configuration: {message}

Error message

invalid block export configuration: {message}

What it means

spawn_block_export_queue is the single entry point for the block-export pipeline and runs BlockExportConfig::check() first, panicking with the failed rule's message if the config is invalid. This is a deliberate fail-fast: every constructor (CLI, tests, programmatic) must pass a sane config, and misconfiguration aborts at startup rather than corrupting an export mid-run.

Source

Thrown at linera-core/src/chain_worker/export.rs:535

/// Spawns the process-wide export queue task and returns the handle chain workers push to.
///
/// The task runs until every clone of the returned handle is dropped, and reads only from
/// `storage` — never through a chain worker, whose TTL a touch would reset.
pub fn spawn_block_export_queue<S, P>(
    storage: S,
    node_provider: Arc<P>,
    config: BlockExportConfig,
    own_public_key: Option<ValidatorPublicKey>,
) -> BlockExportHandle
where
    S: Storage + Clone + Send + Sync + 'static,
    P: ValidatorNodeProvider + Send + Sync + 'static,
    P::Node: Send + Sync,
{
    // Enforced here rather than only at the CLI: every constructor, tests included, must go
    // through it, and an invalid config panics at startup instead of mid-export.
    if let Err(message) = config.check() {
        panic!("invalid block export configuration: {message}");
    }
    let (blocks, receiver) = mpsc::channel(config.queue_size);
    let progress: SharedProgress = Arc::default();
    let tips: SharedTips = Arc::default();
    let queued_bytes = Arc::new(std::sync::atomic::AtomicUsize::new(0));
    let queue_bytes_budget = config.queue_bytes;
    let max_in_flight_total = config.max_in_flight_total;

    let task = BlockExportQueue {
        storage,
        node_provider,
        config,
        own_public_key,
        latest_epoch: None,
        committee: None,
        committee_dirty: false,
        admin_chain_id: None,
        ticks_until_scan: 0,

View on GitHub (pinned to 6c226ddcb3)

Solutions

1. Read the panic message — it names the exact field and rule (e.g. 'block export queue size must be greater than zero'); fix that field.
2. Prefer deriving from the defaults (queue_size 1024, queue_bytes 256 MiB, …) and overriding individual fields instead of constructing from scratch.
3. If constructing configs programmatically, run config.check()? yourself first and surface the error instead of panicking.

Example fix

// before
let config = BlockExportConfig { queue_size: 0, ..Default::default() };
spawn_block_export_queue(config, ...); // panics

// after
let config = BlockExportConfig { ..Default::default() }; // queue_size = 1024
config.check()?; // surface a Result, don't panic
spawn_block_export_queue(config, ...);

// Rust
let mut config = BlockExportConfig::default(); // sane baseline (queue_size 1024, queue_bytes 256 MiB, ...)
// apply overrides, then:
if let Err(msg) = config.check() {
    return Err(format!("invalid block export configuration: {msg}"));
}
spawn_block_export_queue(config, ...);

fn valid_export_config(config: &BlockExportConfig) -> bool { config.check().is_ok() }

When it happens

Trigger: Any BlockExportConfig with a zero limit or inverted bounds reaches spawn: certificate_upload_batch_size == 0, queue_size == 0, queue_bytes == 0, max_in_flight_per_destination == 0, max_in_flight_total == 0, max_in_flight_total < max_in_flight_per_destination, max_catch_up_blocks == 0, or a zero idle_catch_up_interval. Typical sources: a config file missing fields that deserialize to 0, manual construction in tests, or CLI overrides zeroing a value.

Common situations: Hand-rolled configs in tests that only set a few fields; config files from an older/newer version missing newer knobs (defaulting to 0); scripts copying a partial config template; 'disable this feature by setting it to 0' assumptions colliding with the validator.

Related errors

• owner should be different from spender
• Returned AccountInfo should have code: Some(...) and so code
• Returned AccountInfo should have code: Some(...) and so code
• unexpected query response: {other:?}
• Cannot apply default storage because the feature 'rocksdb' w

AI-assisted analysis of linera-io/linera-protocol@6c226ddcb3 (2026-08-22). Data as JSON: /api/errors/b7e197f8e9da5e86. Report an issue: GitHub.