Rather than hoping someone reopens a bug themselves when going through all of the failures and classifying a closed bug, I think Orangefactor bot should just do the reopening itself when it goes through and comments in the bug. This might be tricky or accidentally reopen bugs that have actually been fixed in the last one to seven days (when the daily/weekly crons run), so maybe only do this if the last_resolved time for the bug is older than one week?

And maybe only for bugs resolved WORKSFORME? If a bug has actually been "fixed" and pops back up at some later point, it probably warrants a new bug being filed for the new failure. WORKSFORME bugs are just closed from inactivity, so if they come back, they can go back into the old bug.

This isn't a regression from bug 1179821 (it's pre-existing behaviour), so I don't think it blocks it, unless I'm missing something? :-) This would be nice to have, though it quickly gets tricky. eg: we shouldn't open bugs for aurora/b2g, but what about try? etc If the sheriffs could come up with a specific set of requirements (date ranges, repos etc) this would help speed up someone implementing this.