@lazedo - the core file contains the shared memory, but you need to know where to look for xavps. They are linked either in the transaction structure, or registrar/location structure, or from global variables, a matter of what it is done at the moment of generating the crash.
You can use `abort()` (iirc, from cfgutils module )inside kamailio.cfg to trigger a crash at a specific line, so you know what that worker did just before crashing.