#19304 Infer appropriate FaaS `runtime` from interpreter constraints Issue created by huonw Is your feature request related to a problem? Please describe. When building an AWS Lambda or Google Cloud Function, either

runtime

or

complete_platforms

must be specified to imply the Python version/wheels. In many cases, a repo will be using a narrow interpreter constraint, like

==3.10.*

, and hence the runtime is obvious. Describe the solution you'd like Allow

python_aws_lambda_function(handler="foo.py:bar")

alone, and it'll infer the

runtime

(and hence

complete_platforms

#18195) if the ICs of

foo.py

only include a single major version. If they cover more than one, error as ambiguous and require

runtime

as now. And similarly for

python_google_cloud_function

. Describe alternatives you've considered N/A Additional context Add any other context or screenshots about the feature request here. pantsbuild/pants