(Well, this is not an issue but rather my fault...)

I forgot to change PROJECT_ID to my real project id.
and run 'python configure.py --action=get', then I got this error.

{
  "error": {
    "code": 500,
    "message": "[OTHER_INTERNAL_ERROR]: Error in Processor [REMOTE_CONFIG_EXPERIMENT_GROUPS_STAGE] getting experiment groups.",
    "status": "INTERNAL"
  }
}

The error said nothing about 'wrong project id' or something.

Can't it know real project id from service-account.json?
or at least show error message like 'You haven't set your PROJECT_ID'?