What causes "IPC connection closed unexpectedly." in glzr-io/glazewm?

Restart the watcher/main WM processes so a fresh IPC connection is established

IPC connection closed unexpectedly.

Error message

IPC connection closed unexpectedly.

What it means

The watcher process keeps an open IPC connection to the main WM while it watches managed window handles. If the event stream returns `None` — the WebSocket closed without the WM first sending `WmEvent::ApplicationExiting` — the watcher treats this as an abnormal shutdown and bails.

Solutions

Restart the watcher/main WM processes so a fresh IPC connection is established
Check the main WM logs for a crash explaining the abrupt disconnect
If intentional cleanup is needed, have the WM emit `WmEvent::ApplicationExiting` before closing the IPC connection

Defensive patterns

Strategy: try-catch

Try / catch

match watcher::watch_managed_handles() {
  Ok(()) => {}
  Err(e) if e.to_string().contains("IPC connection closed unexpectedly") => {
    tracing::warn!("WM exited without ApplicationExiting event; cleaning up");
  }
  Err(e) => return Err(e),
}

Prevention

Ensure the WM emits WmEvent::ApplicationExiting before shutting down
Monitor the WM process health from the watcher
Implement reconnect/backoff if the connection should be transient

When it happens

Trigger: The main glazewm.exe process is killed/crashes, the IPC socket drops mid-session, or the watcher loses the connection before receiving the graceful `ApplicationExiting` event.

Common situations: Force-killing the WM from Task Manager, WM crash, system shutdown forcibly terminating the parent, or an IPC server bug closing the socket.

Understand the failure class

Background: ECONNREFUSED and "connection refused" / "could not connect to server" errors: what they mean and how to fix them — this error's family across 44 libraries.

Connection failures: ECONNREFUSED, ECONNRESET, and friends — why connections get refused, reset, or dropped.

Related errors

AI-assisted analysis of glzr-io/glazewm@5709ad0a3c (2026-09-08). Data as JSON: /api/errors/d21f2da97d7c4e4f. Report an issue: GitHub.

Appendix: source

Thrown at packages/wm-watcher/src/main.rs:136

    match event_data {
      Some(WmEvent::WindowManaged { managed_window }) => {
        if let ContainerDto::Window(window) = managed_window {
          tracing::info!("Watcher added handle: {}.", window.handle);
          handles.push(window.handle);
        }
      }
      Some(WmEvent::WindowUnmanaged {
        unmanaged_handle, ..
      }) => {
        tracing::info!("Watcher removed handle: {}.", unmanaged_handle);
        handles.retain(|&handle| handle != unmanaged_handle);
      }
      Some(WmEvent::ApplicationExiting) => {
        return Ok(());
      }
      Some(_) => unreachable!(),
      None => {
        anyhow::bail!("IPC connection closed unexpectedly.")
      }
    }
  }
}

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