We are encountering a high rate of failure with some of our tests after upgrading to Python 3.9.6. > python3 -m green --run-coverage --cov-config-file my_lib.coveragerc --junit-report ...

Python 3.9 is the system Python version on Fedora 33 and above, and has been GA since 10/2020. Python 3.9 should be supported by aws-sam-cli.