The message
++ WARN: could not open input stream...
may mean that have to run this as root on OSX. If I recall correctly OSX restricts access to the CD drive for certain kinds of access I think for security reasons. And only one application can have "exclusive" access. So if another device as access already to the CD drive then another program won't be able to get access. So also check that nothing else is accessing the drive.
The fact that you were able to compile libcdio and run that program means that certain things do work. To get an idea of what works and what doesn't work run the tests via "make check".
Finally OSX support on libcdio has been weak for several reasons. First traditionally has been a kind of secrecy in how you control and get access to the DVD device. Perhaps that's now fixed. I believe libcdio uses and older Mach/BSD compatibility calls still.
The second problem at least from my standpoint has been that I don't own a OSX box and have rarely had access to one for testing libcdio. So I can't test it. But I think others in the project do and do test this pretty regularly.