zed-industries/zed · error

native watcher initialized

Error message

native watcher initialized

What it means

A post-condition guard in the native watch path: ensure_native_watcher() was just called successfully, so the native_watcher field behind the mutex is expected to be Some. The expect fires only if that invariant is broken — ensure_native_watcher succeeded without installing the watcher (a logic contradiction) or another thread tore the watcher down between the two calls. It is an internal consistency check, not an input-driven error.

Source

Thrown at crates/fs/src/fs_watcher.rs:1000

    }

    pub fn remove(&self, id: WatcherRegistrationId) {
        let mut state = self.state.lock();
        let Some((path, mode)) = state.remove_registration(id) else {
            return;
        };
        drop(state);
        self.unwatch(path.as_path(), mode).log_err();
    }

    fn watch(&self, path: &Path, mode: WatcherMode) -> anyhow::Result<()> {
        match mode {
            WatcherMode::Native => {
                self.ensure_native_watcher()?;
                self.native_watcher
                    .lock()
                    .as_mut()
                    .expect("native watcher initialized")
                    .watch(
                        path,
                        if cfg!(any(target_os = "windows", target_os = "macos")) {
                            notify::RecursiveMode::Recursive
                        } else {
                            notify::RecursiveMode::NonRecursive
                        },
                    )?;
            }
            WatcherMode::Poll => {
                self.ensure_poll_watcher()?;
                self.poll_watcher
                    .lock()
                    .as_mut()
                    .expect("poll watcher initialized")
                    .watch(path, notify::RecursiveMode::Recursive)?;
            }
        }

View on GitHub (pinned to f4178619ac)

Solutions

1. Have ensure_native_watcher return the &mut watcher it guaranteed, removing the second lock+expect
2. Treat None as a retryable state: re-run ensure_native_watcher and try again instead of panicking
3. Hold the same lock across ensure + use so teardown cannot interleave

When it happens

Trigger: Thrown at crates/fs/src/fs_watcher.rs:1000 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/b182bdc5b38be7a4. Report an issue: GitHub.