It looks like https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=820963 to me. Looking at the Debian changelog, it seems that the Ubuntu delta could be dropped at this point for Zesty.
** Bug watch added: Debian Bug tracker #820963 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=820963 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1576187 Title: backuppc/smb: BackupPC failes to backup SMB shares after smbclient update To manage notifications about this bug go to: https://bugs.launchpad.net/backuppc/+bug/1576187/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs