toolchain:python's "latest" was platform.python_version(), so the verdict
depended on the machine running the gate: setup-python "3.x" gave kuhyx/spellcode
3.15.0 on one runner and 3.14.8 on another, making its transitive:pyodide
allowlist entry dead (exit 2) on one and required (exit 1) on the other.
Now registries/toolchain.python_latest() reads python.org's release API
(is_published, pre_release=false), keeps only exact "Python X.Y.Z" names (the
feed also lists "Python install manager 26.4"), and takes the newest stable.
The never_cached() carve-out is gone: it existed because a cached
*interpreter* version from an older runner image (3.13.15) was served to a
3.14.7 job in screen-locker's CI. A registry answer is safe to cache, so
python now goes through the normal TTL cache, prefetch, and offline fallback
(expired cache -> DEGRADED; no cache -> unavailable), never the local
interpreter.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A4VrLZn9YjhPuoxTj54WKk
