logger.error does not output to stderr

[yank666]

I want to add more detailed error describe in stderr if a step faild , but when i use logger.error print ，running.stderr dosen't print my error log

if __name__=="__main__":
    with Runner('first_flow.py', show_output=True, pylint=False).run() as running:
        print(running.stderr)

here is my simple workflow

from logging import getLogger
from metaflow import FlowSpec, step, current

logger = getLogger(__name__)

class HelloFlow(FlowSpec):
    def __init__(self, use_cli=True):
        super().__init__(use_cli)
        self.doc = None

    @step
    def start(self):


        self.next(self.hello)

    @step
    def hello(self):
        logger.error(f"HelloFlow failed to hello， {current.run_id}")
        raise ValueError("error again")
        self.next(self.end)


   

    @step
    def end(self):
        pass

[savingoyal]

you might need to configure logger to emit to stderr

handler = logging.StreamHandler(sys.stderr)
logger.addHandler(handler)

[yank666]

sorry , it nor work. When i fix code as you shown, stderr still can't catch error message

And ,another question if you konw, if workflow failed ,how can i exactly get the step that failed