Stdio.File()->notify

Hello!

I have a question about the notify method in Stdio.File which I can't get
to work. Maybe I'm using it wrong or maybe it just doesn't work, I don't
know.

I'd like to listen for changes in a directory:

Stdio.File dir = Stdio.File("/my/dir");
dir->notify(
    Stdio.DN_MULTISHOT |
    Stdio.DN_MODIFY |
    Stdio.DN_CREATE |
    Stdio.DN_DELETE |
    Stdio.DN_RENAME,
    lambda() {
        werror("Hello\n");
    }
);

but nothing seems to happen. Am I doing something wrong?

And yes, I'm using Linux.

Regards
# Pontus