Re: [PATCH v5 06/15] index-helper: add --detach

On Wed, 2016-04-20 at 06:50 +0700, Duy Nguyen wrote:

On Wed, Apr 20, 2016 at 6:28 AM, David Turner <
dturner@twopensource.com> wrote:

quoted

@@ -317,6 +320,8 @@ int main(int argc, char **argv)
        if (fd < 0)
                die_errno(_("could not set up index-helper

socket"));

+       if (detach && daemonize(&daemonized))
+               die_errno(_("unable to detach"));

At the least, I think we need to redirect both stdout and stderr to a
file, so we can catch errors. The watchman patch uses warning() to
report errors, for example. And there is always a chance of die().

Then we need to report the errors back. I faced the same problem with
daemonizing git-gc, but I'm not sure if we can do exactly the same
here like in commit 329e6e8 (gc: save log from daemonized gc --auto
and print it next time - 2015-09-19)

I'll add in code to log errors.  I'm not sure where it would make sense
to report the errors.  Generally, for errors during a client operation,
we would like to report them to the client, but the client might have
already disconnected.  I guess in that case it's OK if they just go to
the log?  The client could warn on a timeout while waiting for index
-helper and direct people to the log.