Python: Blender does not print error

Question

I write Add-on using two callback functions, modal timer operator and binary module. When I develop this Add-on, then I write bug sometimes, but Python sometimes silently "die" and no error is printed to terminal. Do you have any advice?

Edit: problem was in Python binary module. Following code was wrong:

session_SessionObject *session = session_list[session_id];
if(session != NULL) {
    PyObject_CallMethod((PyObject*)session, "cb_receive_layer_destroy", "(IH)",
            node_id, layer_id);
}
return;

because it didn't check for return value of PyObject_CallMethod and it didn't try to "catch" errors from Python callback method. Following code is right:

session_SessionObject *session = session_list[session_id];
if(session != NULL) {
    PyObject *result = NULL;
    result = PyObject_CallMethod((PyObject*)session, "cb_receive_layer_destroy", "(IH)",
            node_id, layer_id);
    if(result == NULL || PyErr_Occurred() != NULL) {
        PyErr_Print();
    }
}
return;