    def spawn_home_error(self):
        """Extra message pointing users to try spawning again from /hub/home.

        Should be added to `self.extra_error_html` for any handler
        that could serve a failed spawn message.
        """
        home = url_path_join(self.hub.base_url, 'home')
        return (
            "You can try restarting your server from the "
            f"<a href='{home}'>home page</a>."
        )
Extra message pointing users to try spawning again from /hub/home.

Should be added to `self.extra_error_html` for any handler
that could serve a failed spawn message.
jupyterhub/handlers/base.py