Sorry, I somehow attached an old version of the patch. This one should be correct.

Steven: Redirection relies on a shell - the native 'run a process' interface that the installer uses can't do that. There are ways to work around this, but I think this approach makes sense.

It exits early because stdout and stderr don't go anywhere, so once either of them has filled up a fairly small buffer, attempts to write to it throw an error. I'd love to see that fixed, but it's been known about for years (see issue 706263), and it seems unlikely to change any time soon.