I am having trouble finding this information, and trial and error is telling me that the value is very high. So I figured I ask the community to see if anyone knows and can
The limits depend on the used filesystem - OSX uses HFS Plus by default...
The only official documents I can point to are the HFS Plus spec which document the limit of 255 for filename length.
Wikipedia hints that the max path length on HFS Plus is "unlimited".
Perhaps contacting Apple Dev support is the most reliable way to get exact statements about limits.