Why is dev_appserver.py reporting "no such file or directory" after today's gcloud components update

It looks like there's an active issue on Google's issue tracker (opened on Oct 2, 2018) pertaining to this:

After updating to the Python (2.7) extensions for GAE to version 1.9.76, I am no longer able to run my code with dev_appserver.py

As of Oct 3, a fix appears to be in the works, but for now they suggest downgrading Google Cloud SDK to version 218.0.0:

It seems like you are affected by a known issue regarding ‘dev_appserver.py’ breaks in Google Cloud SDK version [219.0.1]. App Engine specialists are currently working to resolve it. However there is no ETA at this moment. As a workaround you can downgrade the Google Cloud SDK version using this command:

gcloud components update --version 218.0.0

The assignee of the issue will post an update on that issue when it has been resolved.

UPDATE (OCT 9, 2018): Cloud SDK version 220.0.0, which fixes the dev_appserver.py issue, is now available. I updated (via gcloud components update) and verified that it works. (Note: there are already a couple of complaints on the Issue Tracker that dev_appserver.py takes too long to load now. I didn't notice a significant difference from version 218, but I didn't compare timings.)