Comment 6 for bug 1672571

Quick dummy test:

With Xtrabackup 2.4.6 and 5.7.17 PS:

# Backup

/home/shahriyar.rzaev/Percona_Xtrabackups/xb_2.4/usr/local/xtrabackup/bin/xtrabackup --defaults-file=/home/shahriyar.rzaev/sandboxes/rsandbox_Percona-Server-5_7_17/master/my.sandbox.cnf --user=jeffrey --password='msandbox' --target-dir=/home/shahriyar.rzaev/backup_dirs/ps_5.7_master//full/2017-03-20_08-38-19 --backup --host=localhost --port=20192 --binlog-info=ON

170320 08:38:53 Backup created in directory '/home/shahriyar.rzaev/backup_dirs/ps_5.7_master/full/2017-03-20_08-38-19/'
MySQL binlog position: filename 'mysql-bin.000035', position '194', GTID of the last change '00020192-1111-1111-1111-111111111111:1-68'

# Prepare
/home/shahriyar.rzaev/Percona_Xtrabackups/xb_2.4/usr/local/xtrabackup/bin/xtrabackup --defaults-file=/home/shahriyar.rzaev/sandboxes/rsandbox_Percona-Server-5_7_17/master/my.sandbox.cnf --user=jeffrey --password='msandbox' --target-dir=/home/shahriyar.rzaev/backup_dirs/ps_5.7_master//full/2017-03-20_08-38-19 --prepare --host=localhost --port=20192 --binlog-info=ON

InnoDB: Starting crash recovery.
InnoDB: xtrabackup: Last MySQL binlog file position 194, file name mysql-bin.000035

# from log:

$ cat xtrabackup_binlog_info
mysql-bin.000035 194 00020192-1111-1111-1111-111111111111:1-68

Result:
Could not spot the difference between backup/prepare