Upload mirroring with lftp

By default, many FTP servers don't list '.' and '..' (current and parent directories) which confuses lftp when uploading a mirorr copy. What happens is that lftp sends a "list" command and, if it's in an empty directory, lftp gets nothing back.

Solution: use

set ftp:list-options -a

This forces the remote ftp server to include '.' and '..' to keep lftp happy.