release: bring main up to develop (Teller v1.12.0 backports + audit follow-up)

.github/scripts/check_pin_freshness.py

@@ -0,0 +1,235 @@
+#!/usr/bin/env python3
+"""Audit GitHub Actions pin freshness against the upstream registries.
+
+`check_action_pins.py` validates pin **shape** — does the @ref match the
+policy bucket. This script validates **freshness** — does the @ref still
+resolve to something upstream, and does the trailing `# vN.M.P` comment
+on a SHA pin still match the tag's current SHA?
+
+Filed as #136 after PR #121 surfaced `astral-sh/setup-uv@v5` going
+silently dead — the tag stopped resolving to anything in March 2026,
+producing 0-jobs / 0-seconds CI failures. The shape gate doesn't catch
+that class; this freshness gate does.
+
+Behaviour:
+
+- Walks every workflow + composite-action file via the same
+  `parse_workflow` machinery as `check_action_pins.py`.
+- For each tag pin (`@v8`, `@v8.0.0`): GET
+  `https://api.github.com/repos/<action>/git/refs/tags/<ref>`. A 404 means
+  the tag no longer exists upstream — emit `::warning::` (or `::error::`
+  under strict mode).
+- For each SHA pin (`@<40-hex>` + trailing `# vN.M.P` comment): GET
+  `/repos/<action>/git/refs/tags/<comment-version>` to fetch the tag's
+  current SHA. If the tag exists and resolves to a different SHA than
+  the pin, the upstream re-tagged — warn (potential supply-chain shift).
+  If the tag's SHA is a tag object (annotated tag), dereference one
+  level via `git/tags/<sha>` to get the commit SHA before comparing.
+- API failures (network, 4xx other than 404, 5xx) downgrade to
+  `::warning::` — the gate's job is to surface drift, not be a
+  transient-network tripwire.
+
+Default: warn-not-fail (`exit 0` even on findings, with annotations).
+With `PIN_FRESHNESS_STRICT=1`, findings escalate to errors (`exit 1`),
+matching the `ASPIRATIONAL_STRICT=1` toggle pattern from #153.
+
+Exit codes:
+  0 — every pin resolves cleanly OR strict mode is off and findings
+      are surfaced as warnings only
+  1 — strict mode is on and one or more pins failed freshness checks
+  2 — script-level error (workflows dir missing, parse failure, no
+      `GITHUB_TOKEN` set so we can't query the API)
+
+Usage (from repo root, in CI with token):
+
+    GITHUB_TOKEN=... python .github/scripts/check_pin_freshness.py
+"""
+
+from __future__ import annotations
+
+import importlib.util
+import json
+import os
+import sys
+import urllib.error
+import urllib.request
+from pathlib import Path
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from types import ModuleType
+
+# Reuse `parse_workflow`, `_collect_yaml_files`, `_VERSION_COMMENT_RE`,
+# `_SHA_RE`, etc. from check_action_pins.py rather than duplicate them.
+# Importlib-based load mirrors the test pattern used elsewhere in the
+# repo so this script stays standalone (no setup.py wiring needed).
+_SCRIPT_DIR = Path(__file__).parent
+
+
+def _load_pin_module() -> ModuleType:
+    spec = importlib.util.spec_from_file_location(
+        "check_action_pins", _SCRIPT_DIR / "check_action_pins.py"
+    )
+    if spec is None or spec.loader is None:
+        msg = "could not load check_action_pins.py"
+        raise RuntimeError(msg)
+    module = importlib.util.module_from_spec(spec)
+    # Register in sys.modules BEFORE exec_module — `@dataclass` walks
+    # `sys.modules[cls.__module__]` while processing the class, and the
+    # ActionRef dataclass would AttributeError without this line.
+    sys.modules[spec.name] = module
+    spec.loader.exec_module(module)
+    return module
+
+
+_pins = _load_pin_module()
+_API_BASE = "https://api.github.com"
+
+
+def _fetch_json(url: str, token: str) -> dict[str, object] | None:
+    """GET a GitHub API URL, return parsed JSON or None on any failure.
+
+    Failures (404, 5xx, network, JSON-parse) all collapse to None — the
+    caller decides how to surface them. Keeps this gate from being a
+    transient-CI tripwire.
+    """
+    req = urllib.request.Request(  # noqa: S310 — fixed api.github.com host
+        url,
+        headers={
+            "Authorization": f"Bearer {token}",
+            "Accept": "application/vnd.github+json",
+            "X-GitHub-Api-Version": "2022-11-28",
+        },
+    )
+    try:
+        with urllib.request.urlopen(req, timeout=10) as response:  # noqa: S310
+            payload = json.loads(response.read().decode("utf-8"))
+    except urllib.error.URLError, TimeoutError, json.JSONDecodeError:
+        return None
+    return payload if isinstance(payload, dict) else None
+
+
+def _resolve_tag_sha(action: str, tag: str, token: str) -> str | None:
+    """Return the commit SHA the tag points at, or None on missing/error.
+
+    Annotated tags resolve via two GETs: first `/git/refs/tags/<tag>` to
+    get the tag-object SHA, then `/git/tags/<obj>` to dereference to the
+    commit. Lightweight tags resolve in one GET (the ref's `object.sha`
+    is the commit directly).
+    """
+    ref = _fetch_json(f"{_API_BASE}/repos/{action}/git/refs/tags/{tag}", token)
+    if ref is None:
+        return None
+    obj = ref.get("object")
+    if not isinstance(obj, dict):
+        return None
+    obj_type = obj.get("type")
+    obj_sha = obj.get("sha")
+    if not isinstance(obj_sha, str):
+        return None
+    if obj_type == "commit":
+        return obj_sha
+    if obj_type == "tag":
+        # Annotated tag — dereference to the commit it points at.
+        annotated = _fetch_json(f"{_API_BASE}/repos/{action}/git/tags/{obj_sha}", token)
+        if annotated is None:
+            return None
+        inner = annotated.get("object")
+        if isinstance(inner, dict):
+            inner_sha = inner.get("sha")
+            if isinstance(inner_sha, str):
+                return inner_sha
+    return None
+
+
+def _check_tag_pin(ref: object, token: str) -> str | None:
+    """Tag pin: ensure the upstream tag still exists. Returns warning text or None."""
+    tag = ref.pin  # type: ignore[attr-defined]
+    sha = _resolve_tag_sha(ref.action, tag, token)  # type: ignore[attr-defined]
+    if sha is None:
+        return (
+            f"{ref.action}@{tag} — upstream tag no longer resolves "  # type: ignore[attr-defined]
+            "(404 or API failure). If 404, the tag was deleted/renamed; "
+            "bump to a current tag or SHA pin."
+        )
+    return None
+
+
+def _check_sha_pin(ref: object, token: str) -> str | None:
+    """SHA pin: trailing tag comment must still resolve to the same SHA."""
+    if not ref.comment:  # type: ignore[attr-defined]
+        return None  # shape audit owns the missing-comment case
+    match = _pins._VERSION_COMMENT_RE.search(ref.comment)  # type: ignore[attr-defined]
+    if not match:
+        return None
+    documented_tag = match.group(0)
+    upstream_sha = _resolve_tag_sha(ref.action, documented_tag, token)  # type: ignore[attr-defined]
+    if upstream_sha is None:
+        return (
+            f"{ref.action}@{ref.pin[:8]}… (commented `{documented_tag}`) "  # type: ignore[attr-defined]
+            "— upstream tag no longer resolves; comment may be stale."
+        )
+    if upstream_sha.lower() != ref.pin.lower():  # type: ignore[attr-defined]
+        return (
+            f"{ref.action}@{ref.pin[:8]}… (commented `{documented_tag}`) "  # type: ignore[attr-defined]
+            f"— upstream tag has been re-tagged to "
+            f"{upstream_sha[:8]}…; pin no longer matches the documented tag."
+        )
+    return None
+
+
+def main() -> int:
+    token = os.environ.get("GITHUB_TOKEN", "")
+    if not token:
+        print(
+            "::error::GITHUB_TOKEN required for pin-freshness audit "
+            "(API rate limit + private-repo access)."
+        )
+        return 2
+
+    yml_files = _pins._collect_yaml_files()
+    if not yml_files:
+        print("::error::no workflow / composite-action files found")
+        return 2
+
+    refs = []
+    for path in yml_files:
+        refs.extend(_pins.parse_workflow(path))
+
+    strict = os.environ.get("PIN_FRESHNESS_STRICT", "") == "1"
+    findings: list[tuple[object, str]] = []
+    for ref in refs:
+        if not ref.pin:
+            continue  # shape audit catches missing-@
+        if _pins._SHA_RE.match(ref.pin):
+            problem = _check_sha_pin(ref, token)
+        else:
+            problem = _check_tag_pin(ref, token)
+        if problem is not None:
+            findings.append((ref, problem))
+
+    severity = "error" if strict else "warning"
+    for ref, problem in findings:
+        print(f"::{severity} file={ref.file},line={ref.line}::{problem}")  # type: ignore[attr-defined]
+
+    summary = (
+        f"Pin-freshness audit: {len(refs)} pins checked across "
+        f"{len(yml_files)} files; {len(findings)} finding(s)"
+    )
+    # Surface the finding count as a workflow output so the calling
+    # workflow can decide whether to open a tracking issue. Skipped when
+    # GITHUB_OUTPUT isn't set (local runs / tests).
+    output_path = os.environ.get("GITHUB_OUTPUT", "")
+    if output_path:
+        with Path(output_path).open("a", encoding="utf-8") as fh:
+            fh.write(f"findings_count={len(findings)}\n")
+    if findings:
+        suffix = " (strict — failing)" if strict else " (warn-only)"
+        print(summary + suffix + ".")
+        return 1 if strict else 0
+    print(summary + ".")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

.github/scripts/check_required_contexts.py

@@ -55,6 +55,14 @@
         "workflow_run-triggered after release.yml + workflow_dispatch only;"
         " opens its own roll-up PR (which goes through ci.yml as normal)."
     ),
+    "pin-freshness-audit.yml": (
+        "Weekly cron + workflow_dispatch; warn-only by default with auto-"
+        " filed tracking issue. Never appears on PR check sets."
+    ),
+    "changelog-prestage.yml": (
+        "workflow_dispatch only; opens its own pre-stage PR before a"
+        " release PR is opened. Never appears on PR check sets."
+    ),
 }