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Python runtime lifecycle

Rule ID: check_python_runtime_lifecycle · Category: environment · Section: python_env Severity: warning inside the retiring window, error past end-of-support · Profiles: deploy, full · Tier: core

What it checks

The target Python version against its published Azure Functions end-of-support date. The check warns when the target runtime is retiring and fails once it is past end-of-support.

The target version is resolved the same way as check_python_version: from --target-python when supplied, otherwise the interpreter running the doctor.

Why it matters

Azure Functions retires Python runtimes on a published schedule. Deploying on a runtime at or past end-of-support risks losing security updates and, eventually, the ability to deploy at all.

Symptoms

Deployments on a retiring runtime keep working until the end-of-support date, then fail or lose patching; upgrades left too late force a rushed migration.

Example finding

Python 3.10.12 support is expected to end in October 2026; plan an upgrade
to a newer Python (3.12+) before then.

The finding carries auditable evidence (Finding Contract v2): expected, actual, source_url, last_verified, and catalog_version from the version-controlled compatibility catalog.

How to fix

Target a Python version with a long support runway (3.12+). Upgrade a retiring runtime before its Azure Functions end-of-support date.

Reference