Python gunicorn引导工人在回路上

我试图在heroku上部署一个flask应用程序，但在日志中，我在循环中不断遇到这个错误，我没有使用任何docker/容器

我使用的是

gunicorn==19.9.0

和

python-3.7.7

我的程序文件包含->

web:gunicorn app:app

2021-01-01T20:07:10.172164+00:00 app[web.1]: [2021-01-01 20:07:10 +0000] [2363] [INFO] Booting worker with pid: 2363
2021-01-01T20:07:10.841592+00:00 app[web.1]: [2021-01-01 20:07:10 +0000] [2371] [INFO] Booting worker with pid: 2371
2021-01-01T20:07:11.478375+00:00 app[web.1]: [2021-01-01 20:07:11 +0000] [2379] [INFO] Booting worker with pid: 2379
2021-01-01T20:07:11.677500+00:00 app[web.1]: [2021-01-01 20:07:11 +0000] [2387] [INFO] Booting worker with pid: 2387
2021-01-01T20:07:12.595348+00:00 app[web.1]: [2021-01-01 20:07:12 +0000] [2395] [INFO] Booting worker with pid: 2395
2021-01-01T20:07:12.815387+00:00 app[web.1]: [2021-01-01 20:07:12 +0000] [2403] [INFO] Booting worker with pid: 2403
2021-01-01T20:07:13.193908+00:00 app[web.1]: [2021-01-01 20:07:13 +0000] [2411] [INFO] Booting worker with pid: 2411
2021-01-01T20:07:13.862270+00:00 app[web.1]: [2021-01-01 20:07:13 +0000] [2419] [INFO] Booting worker with pid: 2419
2021-01-01T20:07:15.142863+00:00 app[web.1]: [2021-01-01 20:07:15 +0000] [2427] [INFO] Booting worker with pid: 2427
2021-01-01T20:07:15.254555+00:00 app[web.1]: [2021-01-01 20:07:15 +0000] [2432] [INFO] Booting worker with pid: 2432
2021-01-01T20:07:16.884513+00:00 app[web.1]: [2021-01-01 20:07:16 +0000] [2443] [INFO] Booting worker with pid: 2443
2021-01-01T20:07:17.027716+00:00 app[web.1]: [2021-01-01 20:07:17 +0000] [2451] [INFO] Booting worker with pid: 2451
2021-01-01T20:07:18.413229+00:00 app[web.1]: [2021-01-01 20:07:18 +0000] [2459] [INFO] Booting worker with pid: 2459
2021-01-01T20:07:18.844276+00:00 app[web.1]: [2021-01-01 20:07:18 +0000] [2467] [INFO] Booting worker with pid: 2467
2021-01-01T20:07:19.835412+00:00 app[web.1]: [2021-01-01 20:07:19 +0000] [2475] [INFO] Booting worker with pid: 2475
2021-01-01T20:07:20.329649+00:00 app[web.1]: [2021-01-01 20:07:20 +0000] [2483] [INFO] Booting worker with pid: 2483