post_command.pyでコマンドが投げられない

[massongit]

$ pipenv run python post_command.py amesh

上記のコマンドを投げると以下のようなエラーが発生します。

$ docker-compose logs
...
hato-bot_1  | [2020-08-15 06:11:30,295] ERROR in app: Exception on / [POST]
hato-bot_1  | Traceback (most recent call last):
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/flask/app.py", line 2447, in wsgi_app
hato-bot_1  |     response = self.full_dispatch_request()
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/flask/app.py", line 1952, in full_dispatch_request
hato-bot_1  |     rv = self.handle_user_exception(e)
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/flask/app.py", line 1821, in handle_user_exception
hato-bot_1  |     reraise(exc_type, exc_value, tb)
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/flask/_compat.py", line 39, in reraise
hato-bot_1  |     raise value
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/flask/app.py", line 1950, in full_dispatch_request
hato-bot_1  |     rv = self.dispatch_request()
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/flask/app.py", line 1936, in dispatch_request
hato-bot_1  |     return self.view_functions[rule.endpoint](**req.view_args)
hato-bot_1  |   File "/usr/src/app/run.py", line 91, in http_app
hato-bot_1  |     client = SlackClient(channel, user)
hato-bot_1  |   File "/usr/src/app/library/clientclass.py", line 55, in __init__
hato-bot_1  |     self.send_user_name = self.client.users_info(user=send_user)[
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/slack/web/client.py", line 1889, in users_info
hato-bot_1  |     return self.api_call("users.info", http_verb="GET", params=kwargs)
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/slack/web/base_client.py", line 215, in api_call
hato-bot_1  |     return self._sync_send(api_url=api_url, req_args=req_args)
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/slack/web/base_client.py", line 341, in _sync_send
hato-bot_1  |     return self._urllib_api_call(
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/slack/web/base_client.py", line 465, in _urllib_api_call
hato-bot_1  |     return SlackResponse(
hato-bot_1  |   File "/usr/src/venv/app-lp47FrbD/lib/python3.8/site-packages/slack/web/slack_response.py", line 195, in validate
hato-bot_1  |     raise e.SlackApiError(message=msg, response=self)
hato-bot_1  | slack.errors.SlackApiError: The request to the Slack API failed.
hato-bot_1  | The server responded with: {'ok': False, 'error': 'user_not_found'}
...