def paths(self):
        """The list of search paths. It is built from registered finders, which
        has ``paths`` property. Can be useful for compilers to resolve internal
        dependencies.
        """
        if not hasattr(self, '_paths'):
            paths = []
            for finder in self.finders:
                if hasattr(finder, 'paths'):
                    paths.extend(finder.paths)
            self._paths = paths
        return self._paths