Re: [PATCH] update hook: redirect _both_ diagnostic lines to stderr upon tag failure

Jim Meyering [off-list ref] writes:

Otherwise, sending the diagnostic to stdout would provoke a protocol failure.

Very true; thanks for the patch.

However, I suspect that we'd want to prevent this by redirecting
on the caller side, so that the hook writers do not have to
worry about the issue.  I haven't looked at the code that runs
the hook for some time but we should be able to do that...