After investigation, it appears that an article in this newsgroup has insanely long overview data (111,497 bytes). It is a spam with a Subject header field of about that size.
As ovsqlite-server implements a limit of 100,000 bytes to detect corrupt overview data at read-time (which is the reason of the expireover failure), the same limit should be implemented at write-time so that such data are not added to the database.
Jesse Rehmer reports an issue in the expireover process with ovsqlite:
After investigation, it appears that an article in this newsgroup has insanely long overview data (111,497 bytes). It is a spam with a Subject header field of about that size. As ovsqlite-server implements a limit of 100,000 bytes to detect corrupt overview data at read-time (which is the reason of the expireover failure), the same limit should be implemented at write-time so that such data are not added to the database.