object.error: Privileged Instruction

[simendsjo]

What does the message in the subject mean?

Here's a testcase (tested on dmd 2.060 on win7 32-bit):
import core.exception;
import core.runtime; // comment out this, and no stacktrace is 
printed

void myAssertHandler(string file, size_t line, string msg = null) 
{ }

static this() {
    setAssertHandler(&myAssertHandler);
    f();
}

version(unittest) {
    void f() {
        //assert(false); // without message, object.error: 
Breakpoint
        assert(false, "aoeu"); // with message, object.error: 
Privileged Instruction
    }
}