Externals in loop should run to completion

[sophiajt]

Describe the bug

From discord:

is there a way to detect when an outside script is finished executing?
Im currently having some code that look like this, but for some reason the next iteration is triggerd before ffmpeg finishes its previous run?

| each {|it|
        ffmpeg -loglevel quiet -y -i $it.path -c copy -c:s srt $"($it.path).mkv"
    }

How to reproduce

See above

Expected behavior

The externals in the loop should run to completion. You shouldn't have to use complete to force them to complete.

Screenshots

No response

Configuration

(unknown)

Additional context

No response

[sophiajt]

If redirection is off, it's possible we spawn and move on. Need to special case that situation

[sophiajt]

It's possible this was fixed by #4803

[sophiajt]

Going to mark this as closed without having a specific complete repro it's a little tricky to know for sure, but we're definitely waiting for more exits now.