zed-industries/zed · error

Failed to initialize timer loop!

Error message

Failed to initialize timer loop!

What it means

LinuxDispatcher::new spawns background worker threads and unwraps thread::Builder::spawn; failure means the OS could not create a thread (RLIMIT_NPROC, cgroup pids.max, memory pressure), so the dispatcher cannot start.

Source

Thrown at crates/gpui_linux/src/linux/dispatcher.rs:59

                    .spawn(move || {
                        for runnable in receiver.iter() {
                            let location = runnable.metadata().location;
                            let spawned = runnable.metadata().spawned;
                            profiler::update_running_task(spawned, location);
                            runnable.run();
                            profiler::save_task_timing();
                        }
                    })
                    .unwrap()
            })
            .collect::<Vec<_>>();

        let (timer_sender, timer_channel) = calloop::channel::channel::<TimerAfter>();
        let timer_thread = std::thread::Builder::new()
            .name("Timer".to_owned())
            .spawn(move || {
                let mut event_loop: EventLoop<()> =
                    EventLoop::try_new().expect("Failed to initialize timer loop!");

                let handle = event_loop.handle();
                let timer_handle = event_loop.handle();
                handle
                    .insert_source(timer_channel, move |e, _, _| {
                        if let channel::Event::Msg(timer) = e {
                            let mut runnable = Some(timer.runnable);
                            timer_handle
                                .insert_source(
                                    calloop::timer::Timer::from_duration(timer.duration),
                                    move |_, _, _| {
                                        if let Some(runnable) = runnable.take() {
                                            let location = runnable.metadata().location;
                                            let spawned = runnable.metadata().spawned;
                                            profiler::update_running_task(spawned, location);
                                            runnable.run();
                                            profiler::save_task_timing();
                                        }

View on GitHub (pinned to f4178619ac)

Solutions

1. Raise ulimit -u or the systemd TasksMax/pids limit
2. Check for thread leaks exhausting the process thread budget
3. Reduce requested worker thread count as a degraded startup mode

When it happens

Trigger: Thrown at crates/gpui_linux/src/linux/dispatcher.rs:59 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zed-industries/zed@f4178619ac (2026-08-20). Data as JSON: /api/errors/4da233376e4a4583. Report an issue: GitHub.