I've seen cases where the reason for the failure just plain isn't in the log. I think his happens when cron isn't able to find an available backend instance (kind of rare, but can happen when things are busy or if you configure a limited number of instances). It will keep trying for a few minutes, then eventually give up and not log anything.
On the same topic, I've seen cron jobs initially marked as "failed", then a couple minutes marked as successful. These seem to be the cases where it couldn't initially find an available instance, then eventually finds one. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/v96FWH4JBJUJ. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
