Error during make on Quickstart setup

I have made it with zero issues through all of the Quickstart setup steps to the point of running make in the local iris project directory where the make fails with the following error:

(venv) chris@litterbox:~/Projects/iris$ make
iris-dev ./configs/config.dev.yaml
[2022-04-26 15:31:42 -0500] [55669] [INFO] Starting gunicorn 20.1.0
[2022-04-26 15:31:42 -0500] [55669] [INFO] Listening at: http://0.0.0.0:16649 (55669)
[2022-04-26 15:31:42 -0500] [55669] [INFO] Using worker: gevent
[2022-04-26 15:31:42 -0500] [55670] [INFO] Booting worker with pid: 55670
[2022-04-26 15:31:42 -0500] [55671] [INFO] Booting worker with pid: 55671
[2022-04-26 15:31:42 -0500] [55672] [INFO] Booting worker with pid: 55672
[2022-04-26 15:31:42 -0500] [55673] [INFO] Booting worker with pid: 55673
[2022-04-26 15:31:42 -0500] [55670] [ERROR] Exception in worker process
Traceback (most recent call last):
File "/home/chris/Projects/iris/venv/lib/python3.9/site-packages/gunicorn/arbiter.py", line 589, in spawn_worker
worker.init_process()
File "/home/chris/Projects/iris/venv/lib/python3.9/site-packages/gunicorn/workers/ggevent.py", line 146, in init_process
super().init_process()
File "/home/chris/Projects/iris/venv/lib/python3.9/site-packages/gunicorn/workers/base.py", line 134, in init_process
self.load_wsgi()
File "/home/chris/Projects/iris/venv/lib/python3.9/site-packages/gunicorn/workers/base.py", line 146, in load_wsgi
self.wsgi = self.app.wsgi()
File "/home/chris/Projects/iris/venv/lib/python3.9/site-packages/gunicorn/app/base.py", line 67, in wsgi
self.callable = self.load()
File "/home/chris/Projects/iris/src/iris/bin/run_server.py", line 36, in load
app = iris.api.get_api(config)
File "/home/chris/Projects/iris/src/iris/api.py", line 5515, in get_api
spawn(update_cache_worker)
File "src/gevent/greenlet.py", line 663, in gevent._greenlet.Greenlet.spawn
AttributeError: type object 'function' has no attribute 'start'
[2022-04-26 15:31:42 -0500] [55670] [INFO] Worker exiting (pid: 55670)

Environment details:
Debian 11 (x86_64)
Python 3.9.2
mysql Ver 8.0.29 for Linux on x86_64 (MySQL Community Server - GPL)

Start by reproducing the failure with make, then inspect src/iris/bin/run_server.py and src/iris/api.py around get_api and update_cache_worker. Trace how the worker is started and verify the local Quickstart setup reaches a running Iris service without the reported AttributeError.