how to see the output of a cron/at jobs while it is still ruing?

The output of a cron or atq job is automatically send by email to the user, when the job is finished.

However I am ruing a time consuming script, and I would like to check that it is ruing properly before it is completed.

I checked in /tmp but there is no relevant file. I grepped in /proc/ but found nothing. I searched in /var/logs, but nothing there as well. However, the output must be saved somewhere before being sent by email (hope it's not being saved in memory). Thus, it should be somewhere.

I know that I can use other solutions (writing the log to a file), but I wonder if there is any trick for this specific case.