Comment 7 for bug 1645774

to anyone who manages to observe the same issue, aside from capturing logs from stderr you can also try using strace like:

strace -f -s65535 -o/tmp/xb.strace innobackupex --user=root --password=****** --tmpdir=/path/to/tmpdir /path/to/backupdir > /tmp/xb.out 2>&1