The TraceHandler that is built into the core runtime is not being called on Access Violation errors. Try this piece of sourcecode:

import std.stdio;
import core.runtime;

Throwable.TraceInfo TraceHandler1(void* ptr){
	writefln("TraceHandler1");
	return null;
}

Throwable.TraceInfo TraceHandler2(void* ptr){
	writefln("TraceHandler2");
	return null;
}

void main(string[] argv){
	Runtime.traceHandler(&TraceHandler1);
	try {
		int[] array = new int[20];
		array[20] = 0;
	}
	catch(Error e){
	}
	
	Runtime.traceHandler(&TraceHandler2);
	
	int* ptr = null;
	*ptr = 0;
}

TraceHandler2 is never being called. I tested this with dmd 2.046, 2.048 and 2.049.