Function run_watched_for 

pub fn run_watched_for(
    program: &str,
    args: &[&str],
    env: &[(&str, &str)],
    stall: Duration,
) -> Result<()>

As run_watched, with the silence budget supplied.

Exists so the stall path itself is testable: a test cannot wait out the real five minutes, and a guard that has never fired is not known to work.