Thanks @piac,
It could either be an incompatibility of the Jackalope plugin when running on Mac (e.g. using windows-specific apis), or it could be a problem with GH on Mac. I’ve created a youtrack item RH-37200 for this so we can investigate what’s going on there.
Jackalope on Rhino for Windows requires Rhino 5 SR9 or greater, as this is the first release that contains the standard space morph wrappers. If Rhino for Mac is using an older RhinoCommon, then this is most likely the problem.
@stevebaer alerted me to what he thinks is going on here. It seems that rh_spacemorph.cpp is not part of the rhcommon_c.xcodeproj …so I’m adding that now and will cite RH-37200. Hopefully, having the functions will contribute to the solution to this problem 
Yep, that was it. This will be fixed in the next RhinoWIP.