Innobackupex DBI doesn't implement --defaults-extra-file

I found a post here: [URL=“Bug #1485006 “Innobackupex DBI doesn't implement --defaults-extr...” : Bugs : Percona XtraBackup moved to https://jira.percona.com/projects/PXB”]https://bugs.launchpad.net/percona-x...p/+bug/1485006[/URL] which describes my problem exactly.

It seems that while version 2.0.x works fine, 2.1.8 is OK, but 2.1.9 no longer considers the --defaults-extra-file

I have checked changelogs etc, but cannot see where (nor why) the --defaults-extra-file is no longer being read for the user/password. This forces us to put the password elsewhere in a less protected file, or put user= and password= on the command line.

Any input?
Thanks

Bill