I just got the same error, DBI related, eventhough I do have Carp/Heavy.pm. It appears I may have be recursing too deeply and ran out of memory. DBI was trying to complain, but couldn't and died attemping to print an error.

So this type of an error maybe related to perl finally just keeling over, DBI trying to print an error with Heavy.pm and perl couldn't get to Heavy.pm before it died.