atuinsh/atuin · error

daemon sent a lag notice as a history event

Error message

daemon sent a lag notice as a history event

What it means

`TailHistoryReply::from_proto` converts daemon tail-stream events into client-side events, but only Started/Ended/Cancelled carry history payloads. A `Lagged` event arriving where a history event was expected is a protocol violation by the daemon, so the client errors out.

Solutions

1. Restart the daemon so client and daemon use matching versions/protocol.
2. Update the atuin binary (and daemon) to the same version.
3. Handle the Lagged event in the tail loop instead of treating every event as a history event (report upstream if reproducible).

fn is_history_event(reply: &TailHistoryReply) -> bool {
    matches!(
        reply.event,
        Some(TailEventProto::Started(_))
            | Some(TailEventProto::Ended(_))
            | Some(TailEventProto::Cancelled(_))
    )
}

match TailHistoryReply::from_proto(reply) {
    Ok(ev) => handle(ev),
    Err(e) if e.to_string().contains("lag notice") => handle_lag(),
    Err(e) => return Err(e),
}

When it happens

Trigger: `atuin history tail` (or the tail streaming API) when the daemon sends a `Lagged` variant inside an event slot that from_proto expects to be a history event.

Common situations: Daemon/client version skew where lag signaling changed; a daemon bug or misrouted gRPC event; missed back-pressure causing lag notices to be misdelivered.

Related errors

• daemon sent an unspecified history tail event
• {message}
• `atuin history tail` requires Atuin to be built with the…
• could not sync records due to version mismatch
• daemon already running

AI-assisted analysis of atuinsh/atuin@900007c480 (2026-09-19). Data as JSON: /api/errors/ec506f6fa0896b53. Report an issue: GitHub.

Appendix: source

Thrown at crates/atuin/src/command/client/history.rs:700

    #[serde(skip_serializing_if = "Option::is_none")]
    duration_ns: Option<i64>,
    #[serde(skip_serializing_if = "Option::is_none")]
    duration: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    success: Option<bool>,
    #[serde(skip_serializing_if = "Option::is_none")]
    finished_at: Option<String>,
}

#[cfg(feature = "daemon")]
impl TailEvent {
    fn from_proto(reply: TailHistoryReply) -> Result<Self> {
        let (kind, history) = match reply.event {
            Some(TailEventProto::Started(history)) => (TailKind::Started, history),
            Some(TailEventProto::Ended(history)) => (TailKind::Ended, history),
            Some(TailEventProto::Cancelled(history)) => (TailKind::Cancelled, history),
            Some(TailEventProto::Lagged(_)) => {
                bail!("daemon sent a lag notice as a history event")
            }
            None => bail!("daemon sent an unspecified history tail event"),
        };
        let timestamp = OffsetDateTime::from_unix_nanos_i64(history.timestamp);
        let author_kind = history.author_kind();

        Ok(Self {
            kind,
            history: History {
                id: history
                    .id
                    .ok_or_else(|| eyre::eyre!("daemon tail event is missing the history id"))?
                    .try_into()?,
                timestamp,
                duration: history.duration,
                exit: history.exit,
                command: history.command,
                cwd: history.cwd,

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