def search_traceback(self, tb):
        """ Inspect a traceback for new paths to add to our path set."""
        new_paths = []
        with self.lock:
            for filename, line, funcname, txt in traceback.extract_tb(tb):
                path = os.path.abspath(filename)
                if path not in self.paths:
                    self.paths.add(path)
                    new_paths.append(path)
        if new_paths:
            self.watch_paths(new_paths)
Inspect a traceback for new paths to add to our path set.