if !(stringslite.HasPrefix(funcname(f), "runtime.debugCall") || stringslite.HasPrefix(funcname(f), "debugCall")) {
		println("trap in unknown function", funcname(f))
		return false
	}
	if !sigctxtAtTrapInstruction(ctxt) {
		println("trap at non-INT3 instruction pc =", hex(ctxt.sigpc()))
		return false
	}

	switch status := sigctxtStatus(ctxt); status {
	case 0: