As per MacPorts Ticket #27819 (https://trac.macports.org/ticket/27819), cdrdao 1.2.3 cannot setup the IODVDServices device on Mac OS X 10.6.x
Sample output:
ERROR: init: no object
ERROR: init: no plugin
ERROR: init: no mmc
ERROR: init: no scsi
ERROR: init: failed
ERROR: Please use option '--device {[proto:]bus,id,lun}|device', e.g. --device 0,6,0, --device ATA:0,0,0 or --device /dev/cdrom
ERROR: Cannot setup device IODVDServices.
Macports identified this as an issue with the overly verbose device names exceeding the buffer size - issue, with patch, at http://trac.macports.org/ticket/27819
The buffer needs to be even larger than 256 bytes- Modern USB SuperDrives give a path >400 chars, so I set it to 1024 to be safe.
Fixed in 1.2.5, upstream is now on github.
And nothing beats the feeling of closing a 9-year old bug.