Error
beat.beat.TimeoutError: Timeout waiting for 'cond' to be true. Waited 10 seconds.
Stacktrace
self = <test_lightmodules.Test testMethod=test_processors>
    def test_processors(self):
        shutil.copytree(
            os.path.join(self.beat_path, "mb/testing/testdata/lightmodules"),
            os.path.join(self.working_dir, "module"),
        )
    
        with http_test_server() as server:
            self.render_config_template(modules=[{
                "name": "test",
                "metricsets": ["json"],
                "namespace": "test",
                # Hard-coding 'localhost' because hostname in server.server_name doesn't always work.
                "hosts": [f"localhost:{server.server_port}"],
            }])
    
            proc = self.start_beat()
    
>           self.wait_until(lambda: self.output_lines() > 0)
tests\system\test_lightmodules.py:32: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
self = <test_lightmodules.Test testMethod=test_processors>
cond = <function Test.test_processors.<locals>.<lambda> at 0x000001A0D352B790>
max_timeout = 10, poll_interval = 0.1, name = 'cond'
    def wait_until(self, cond, max_timeout=10, poll_interval=0.1, name="cond"):
        """
        Waits until the cond function returns true,
        or until the max_timeout is reached. Calls the cond
        function every poll_interval seconds.
    
        If the max_timeout is reached before cond() returns
        true, an exception is raised.
        """
        start = datetime.now()
        while not cond():
            if datetime.now() - start > timedelta(seconds=max_timeout):
>               raise TimeoutError("Timeout waiting for '{}' to be true. ".format(name) +
                                   "Waited {} seconds.".format(max_timeout))
E               beat.beat.TimeoutError: Timeout waiting for 'cond' to be true. Waited 10 seconds.
..\libbeat\tests\system\beat\beat.py:362: TimeoutError