kqueue watcher cannot recursively watch root directory

[valentinegb]

When attempting to recursively watch the root directory (/) using KqueueWatcher, Watcher::watch returns "No such file or directory (os error 2)".

MRE

# Cargo.toml
[package]
name = "notify_kqueue_mre"
edition = "2024"

[dependencies]
notify = { version = "8.1.0", default-features = false, features = ["macos_kqueue"] }

// src/main.rs
use std::{path::Path, sync::mpsc::channel};

use notify::{Config, KqueueWatcher, RecursiveMode, Watcher as _};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let (sender, receiver) = channel();
    let mut watcher = KqueueWatcher::new(sender, Config::default())?;

    watcher.watch(Path::new("/"), RecursiveMode::Recursive)?;

    for _result in receiver {
        // ...
    }

    Ok(())
}

This MRE outputs the following:

Error: Error { kind: Generic("No such file or directory (os error 2)"), paths: [] }

Environment

notify: 8.1.0
Rust: 1.87.0
OS: macOS 26.0 Beta (25A5306g)