Mac builds are tricky... None of the freecad developers has a mac, so we depends on (rare) people willing to try to build and report and follow problems. So it's rarely updated and working out of the box.There is little we can do, unless more mac people are helping.
I think there were reports of pivy working on mac already, so there should be a way to make it work. You are aware, though, that it is not necessary neither for freecad to run neither for making parametric objects, right? It is only needed for Draft and Arch modules, and for making parametric objects with advanced visual behaviour...
About your error here, it's hard to know what's wrong from this info... Have you had a look on the mac-related topics on the freecad forum?
Any chance of getting a prebuilt mac binary with pivy support? I'm anxious to use parameterized objects, and my attempts to build freecad with source have always ended in disaster
Typhon:bin jeremy$ ./FreeCAD
FreeCAD(1575,0x7fff7d676960) malloc: *** error for object 0x7fff7cf72860: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
Abnormal program terminationů