我使用 Python 和 Dash 编写了一个简单的仪表板。我将其部署（试用）在 Heroku 中，并成功构建，但是应用程序处于错误状态。
以下是日志文件的一部分（太长了，但是我可以提供帮助！）。我无法理解该错误，因此将完整的日志粘贴到此处。
heroku logs --tail › Warning: heroku update available from 7.35.0 to 7.42.1. 2020-06-08T21:50:02.817849+00:00 app[web.1]: self.sleep() 2020-06-08T21:50:02.817885+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/arbiter.py", line 360, in sleep 2020-06-08T21:50:02.818331+00:00 app[web.1]: ready = select.select([self.PIPE[0]], [], [], 1.0) 2020-06-08T21:50:02.818366+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/arbiter.py", line 245, in handle_chld 2020-06-08T21:50:02.818656+00:00 app[web.1]: self.reap_workers() 2020-06-08T21:50:02.818694+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/arbiter.py", line 528, in reap_workers 2020-06-08T21:50:02.819143+00:00 app[web.1]: raise HaltServer(reason, self.APP_LOAD_ERROR) 2020-06-08T21:50:02.819238+00:00 app[web.1]: gunicorn.errors.HaltServer: <HaltServer 'App failed to load.' 4> 2020-06-08T21:50:02.819239+00:00 app[web.1]: 2020-06-08T21:50:02.819240+00:00 app[web.1]: During handling of the above exception, another exception occurred: 2020-06-08T21:50:02.819240+00:00 app[web.1]: 2020-06-08T21:50:02.819245+00:00 app[web.1]: Traceback (most recent call last): 2020-06-08T21:50:02.819272+00:00 app[web.1]: File "/app/.heroku/python/bin/gunicorn", line 8, in <module> 2020-06-08T21:50:02.819419+00:00 app[web.1]: sys.exit(run()) 2020-06-08T21:50:02.819420+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/app/wsgiapp.py", line 61, in run 2020-06-08T21:50:02.819576+00:00 app[web.1]: WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run() 2020-06-08T21:50:02.819580+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/app/base.py", line 223, in run 2020-06-08T21:50:02.819779+00:00 app[web.1]: super(Application, self).run() 2020-06-08T21:50:02.819785+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/app/base.py", line 72, in run 2020-06-08T21:50:02.819951+00:00 app[web.1]: Arbiter(self).run() 2020-06-08T21:50:02.819956+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/arbiter.py", line 232, in run 2020-06-08T21:50:02.820155+00:00 app[web.1]: self.halt(reason=inst.reason, exit_status=inst.exit_status) 2020-06-08T21:50:02.820160+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/arbiter.py", line 345, in halt 2020-06-08T21:50:02.820395+00:00 app[web.1]: self.stop() 2020-06-08T21:50:02.820400+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/gunicorn/arbiter.py", line 393, in stop