What is the Unix command to create a hardlink to a directory in OS X?

Question

How do you create a hardlink (as opposed to a symlink or a Mac OS alias) in OS X that points to a directory? I already know the command \"ln target destination\" but that on

Answer 1

Yes it's supported by the kernel and the filesystem, but since it's not intended for general usage it's not exposed to the shell.

You could probably work out which APIs Time Machine uses and wrap them in a commandline tool, but it'd be better to take the hint and steer well-clear.