[arch-general] Debugging third-party library's segfault if its caused by system update?

I use the openni2 library to access an Asus Xtion Pro Live camera, installed from the AUR and working fine up till 2+ weeks ago. After a 2 week holiday, the most recent system update caused segfaults to happen within the library (both before and after rebuilding it), without any change to the code calling the library. Same segfault happens with the simple sample applications included in the library (previously running fine). How do I track down the issue? The library's source code is available, but without knowing it well I'm unsure where to even begin. Normally I'd contact the authors, but as this issue was caused (on my system) by a system update I think I'd need to do some tracking down first.