I am currently the only person who runs the boxm2 code on a Mac, so I'll try to share as much as I know.
First, don't be alarmed by the number of warnings. I see the same but I am able to run the code successfully. With respect to the error, it is indeed a build error - .cl code gets compiled at run time and that is why it only shows up then. The first error seems to be "BUILD ERROR: Error getting function data from server" when trying to build the program for update::pre_inf. While I haven't seen that same error my self, I recently had a strange error at the same functions. I didn't commit the changes since the fix was a little odd. I am attaching a patch with my changes. Basically, changing the order of the inputs in the CL code fixed it for me.
If my changes don't fix your problem, maybe try to iterate through your code and let me know at what point the error is printed. If the fix works, let me know and I can commit to the repository. Also I'm moving the discussion to vxl-users .