What causes "failed to register sigint handler" in atuinsh/atuin?

Run the daemon via the shipped atuin binary, which builds the runtime with enable_all()

failed to register sigint handler

Error message

failed to register sigint handler

What it means

Alongside SIGTERM, atuin-daemon's shutdown_signal() registers a SIGINT listener with tokio::signal::unix::signal(SignalKind::interrupt()). tokio returns Err when the runtime lacks an IO/signal driver or the OS registration fails, and the expect panics with 'failed to register sigint handler', aborting daemon startup.

Source

Thrown at crates/atuin-daemon/src/lib.rs:122

    .await?;

    // Run the daemon event loop
    daemon.run_event_loop().await?;

    // Stop all components on shutdown
    daemon.stop_components().await;

    tracing::info!("daemon shut down complete");
    Ok(())
}

/// Wait for a shutdown signal (Ctrl+C or SIGTERM).
#[cfg(unix)]
async fn shutdown_signal() {
    let mut term = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
        .expect("failed to register sigterm handler");
    let mut int = tokio::signal::unix::signal(tokio::signal::unix::SignalKind::interrupt())
        .expect("failed to register sigint handler");

    tokio::select! {
        _ = term.recv() => {},
        _ = int.recv() => {},
    }
}

/// Wait for a shutdown signal (Ctrl+C).
#[cfg(not(unix))]
async fn shutdown_signal() {
    tokio::signal::ctrl_c()
        .await
        .expect("failed to listen for ctrl+c");
}

View on GitHub (pinned to 202f6ad98e)

Solutions

Run the daemon via the shipped atuin binary, which builds the runtime with enable_all()
Build any hosting runtime with .enable_all() before awaiting daemon code
Raise LimitNOFILE / memory limits if boot-time registration fails

Example fix

// before
let rt = tokio::runtime::Builder::new_current_thread().build()?;

// after
let rt = tokio::runtime::Builder::new_current_thread()
    .enable_all()
    .build()?;

Defensive patterns

Strategy: validation

Validate before calling

let rt = tokio::runtime::Builder::new_multi_thread()
    .enable_all()
    .build()?;
// daemon code must run inside this runtime for SIGINT registration to succeed

Try / catch

match tokio::signal::unix::signal(tokio::signal::unix::SignalKind::interrupt()) {
    Ok(int) => tokio::select! { _ = int.recv() => {} },
    Err(e) => {
        tracing::error!("sigint handler unavailable: {e}; relying on SIGTERM");
        tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
            .expect("sigterm")
            .recv()
            .await;
    }
}

Prevention

Use enable_all() on runtimes that host the daemon
Keep the daemon's fd budget headroom (LimitNOFILE) so signal setup never fails
Avoid embedding daemon shutdown handling in bare executors

When it happens

Trigger: Daemon boot inside a tokio runtime without enable_all()/enable_io(); OS-level failure installing the signal handler under resource exhaustion or a restrictive sandbox.

Common situations: Hosting atuin-daemon in a hand-built runtime; fd-exhausted systems at startup; embedding the daemon in another application's executor.

Related errors

AI-assisted analysis of atuinsh/atuin@202f6ad98e (2026-08-16). Data as JSON: /api/errors/f0f0a0d8586903eb. Report an issue: GitHub.