With the current solution that is implemented as part of WT-8395 to avoid performing rollback to stable with checkpoint snapshot when the database is upgraded from version 10.0.0. This solution caused a regression problem when a 4.4.7+backup database is restored using the latest version, RTS doesn’t fix the database using the checkpoint snapshot due to the lack of WiredTiger version information that is present in the backup.

WiredTiger doesn’t backup the WiredTiger.turtle file as part of the backup operation. Restoring this backup cannot be identified whether the backup was taken from which WiredTiger version to decide whether the RTS can skip rollback using the checkpoint only for the problematic versions.

To avoid the above problem, WiredTiger stores the version information in the WiredTiger backup and the older versions that don't have this version information are treated as having invalid checkpoint snapshots and raise an error when they are getting restored with a new version instead of either corrupting silently or ignoring RTS with checkpoint snapshot. The older version backups can be restored using the older version binary and later they can upgrade it to the newer version. All the newer WiredTiger backups have the WiredTiger version number and they will be performed as normal.