gnus-agent-fetch in batch mode in a cron job

[Julien Cubizolles]

The subject says it all. I'm fetching news through emacs in batch mode
in a cron job but I can't figure out how to get the possible errors
through the mails sent by cron.

In batch mode emacs output everything that should go to the *Messages*
buffer to stderr so cron sends an email each time the job is run, even
without any error. I don't want to receive an email when there is no
problem. Is there a way to get emacs to send only the error messages to
stderr ?

Julien.