Comment 2 for bug 1187071

So the rqg1/table100_innodb_compressed tablespace got created, but its first page has not been initialized/flushed yet before xtrabackup tries to load it into fil_system. 5.1/5.5 InnoDB code would just complain about tablespace ID being non-sensible and omit it from the backup. But in 5.6 it fails with an error in such a case.

So it is a regression in the 5.6 XtraBackup port, which is easy to fix. But there's another problem here that looks related to bug #1177206. Will comment on it there.