The current Mac mightly buildis created on 10.7. The resulting application crashes on startup on 10.9 with an access violation when creating the parser, somewhere in string compare in libstdc++.6.dylib.
Removing the xerces plugin from the binary makes it work.
My initial analysis of the problem is that under 10.7 xerces is built with an incompatible runtime system for C++ (possibly gcc versus llvm).
This turned out to be a very interesting one, and led to bug 866.
The problem may have been that the xerces parser was built incorrectly (see bug 866), and it may have had to do with incompatibility in the API depending on WITH_EXTERNAL_SYNC (fixed in rev 8957..8960).
Still need to confirm the bug has really disappeared with 866 is fixed.