Function start 

pub(crate) fn start(
    s: &Session,
    kind: &str,
    args: Vec<String>,
) -> Result<Job, String>

Starts a job: its file made (“starting”, create), then sioul spam <kind> --job <id> <args> started apart, in a group of its own (on Windows, without a console), so that it goes on when the program that started it ends. Answers at once; the job’s own process says the rest in its file.