use anyhow::Context;use std::fs;use std::path::Path;use std::time::Duration;pub async fn wait_for_pid_file(path: &Path) -> anyhow::Result<String> {    let pid = tokio::time::timeout(Duration::from_secs(2), async {        loop {            if let Ok(contents) = fs::read_to_string(path) {                let trimmed = contents.trim();                if !trimmed.is_empty() {                    return trimmed.to_string();                }            }            tokio::time::sleep(Duration::from_millis(25)).await;        }    })    .await    .context("timed out waiting for pid file")?;    Ok(pid)}pub fn process_is_alive(pid: &str) -> anyhow::Result<bool> {    let status = std::process::Command::new("kill")        .args(["-0", pid])        .status()        .context("failed to probe process liveness with kill -0")?;    Ok(status.success())}async fn wait_for_process_exit_inner(pid: String) -> anyhow::Result<()> {    loop {        if !process_is_alive(&pid)? {            return Ok(());        }        tokio::time::sleep(Duration::from_millis(25)).await;    }}pub async fn wait_for_process_exit(pid: &str) -> anyhow::Result<()> {    let pid = pid.to_string();    tokio::time::timeout(Duration::from_secs(2), wait_for_process_exit_inner(pid))        .await        .context("timed out waiting for process to exit")??;    Ok(())}