Re: [PATCH v3 2/6] run-command: add hide_output to run_processes_parallel_opts

> I may just be missing something, but doesn't "struct child_process"
> already have e.g. "no_stderr", "no_stdout" etc. that we can use?
> I.e. isn't this thing equivalent to running:
>
>         your-command >/dev/null 2>/dev/null
>
> Which is what the non-parallel API already supports.
>
> Now, IIRC if you just set that in the "get_next_task" callback it won't
> work in the parallel API, or you'll block waiting for I/O that'll never
> come or whatever.
>
> But that'll be because the parallel interface currently only suppors a
> subset of the full "child_process" combination of options, and maybe it
> doesn't grok this.
>
> But if that's the case we should just extend the API to support
> "no_stdout", "no_stderr" etc., no?
>
> I.e. hypothetically the parallel one could support 100% of the "struct
> child_process" combination of options, we just haven't bothered yet.
>
> But I don't see why the parallel API should grow options that we already
> have in "struct child_process", instead we should set them there, and it
> should gradually learn to deal with them.
>
> I think it's also fine to have some basic sanity checks there, e.g. I
> could see how for something like this we don't want to support piping
> only some children to /dev/null but not others, and that it should be
> all or nothing (maybe it makes state management when we loop over them
> easier).
>
> Or again, maybe I'm missing something...