Function start_parallel_tasks

pub fn start_parallel_tasks<'a, S, M>(
    tasks: ParallelTasks<'a, S, M>,
    parent_dir: &'a S,
    until: &'a GroupEnd,
) -> ((GroupOfChildren<M>, SpawningMode), Vec<Box<dyn Error>>)
where
    S: Borrow<str> + 'a + ?Sized,
    &'a S: Borrow<str>,

Start a group of parallel child process(es) - tasks, all under the same parent_dir.

This does NOT have a [crate::indicators::SpawningMode] parameter - we behave as if under [crate::indicators::SpawningMode::ProcessAll].

This does NOT check for exit status/stderr of any spawn child processes. It only checks if the actual spawning itself (system call) was successful. If all spawn successfully, then the [crate::indicators::SpawningMode] of the result tuple is [SpawningMode::ProcessAll]. Otherwise the [crate::indicators::SpawningMode] part of the result tuple is either [crate::indicators::SpawningMode::FinishActive] or [crate::indicators::SpawningMode::StopAll], depending on the given until ([GroupEnd]).