[ci-scan-feedback] Read ci-fix head.ref via list/get, not search, to close dedup gap

Open .github/workflows/ci-failure-fix.md and read Step 3 on existing-artifact dedup. Verify the guidance uses list_pull_requests for open PRs and pull_request_read get for merged or closed PRs, because search_pull_requests lacks head.ref. Done means the instructions build the dedup map from returned head.ref values and treat an empty map as not yet enumerated.

Triggering signals

• #134186 / #134134 — help-wanted [ci-fix] PR #134186 (2026-09-18, kind: help, Linked KBE #134061) is an un-deduped twin of confident [ci-fix] PR #134134 (kind: fix, same KBE #134061), both single-file 2-line LibraryImport safe-annotation changes on ci-fix/134061- head branches. #134134 merged 09-18; #134186 remains open. The fixer's Step 3 branch-prefix dedup key never matched. https://github.com/dotnet/runtime/pull/134186
• #134276 / #132616 — this exact fix orphaned twice: last tick's [ci-scan-feedback] PR failed its git push and orphaned as issue #134276 (2026-09-19); a month earlier the same diagnosis orphaned as #132616 (2026-08-21). The fix never landed, so the failure mode reproduced. https://github.com/dotnet/runtime/issues/134276
• Empirical confirmation — search_pull_requests result items expose keys [number, title, state, pull_request, body, labels, ...] with no head/head.ref, whereas list_pull_requests and pull_request_read get both return head.ref (e.g. #134186 -> ci-fix/134061-apple-runner-safety-...). Step 3 instructed the agent to parse head.ref from search results, so the ci-fix/- dedup map was always empty.

Proposed edits

• .github/workflows/ci-failure-fix.md (Step 3 — Existing-artifact dedup, line ~211) — replace the "enumerate every [ci-fix] PR ... parsing head.ref" instruction with an explicit note that search_pull_requests returns no head field, and direct the fixer to read head branches from list_pull_requests (state: open) for open candidates and pull_request_read get for merged/closed candidates. Add that an empty branch map means "not yet enumerated", not "no open PR".

Expected behavior change

The next fixer run builds the <kbe> -> [PRs] dedup map from head.ref values actually present in the response — list_pull_requests for open PRs and pull_request_read get for merged/closed ones — instead of from search_pull_requests items that never carry a head field. This closes the residual dedup gap that let help-wanted PR #134186 be filed against KBE #134061 while #134134 was already open: the fixer detects the open ci-fix/134061- branch and skips with open fix PR #134134 already exists rather than opening a duplicate. This edit lands directly (not as a re-filed feedback issue) because the identical prompt change has now orphaned twice on failed PR pushes (#132616, #134276).

[!NOTE]
AI/Copilot-generated (ci-scan-feedback). Prompt-only edit to .github/workflows/ci-failure-fix.md.

Resolves dotnet/runtime#134276

Generated by CI Outer-Loop Failure Scanner — Feedback · opus48 · 961.2 AIC · ⌖ 19.2 AIC · ⊞ 18.2K · ◷

[!NOTE]
This was originally intended as a pull request, but the git push operation failed.

Original error: The process '/usr/bin/git' failed with exit code 1

Workflow Run: View run details and download bundle artifact

The bundle file is available in the agent artifact in the workflow run linked above.

To create a pull request with the changes:

# Download the artifact from the workflow run
gh run download 35511965948 -n agent -D /tmp/agent-35511965948

# Fetch the bundle into a temporary ref, then update the local branch
git fetch /tmp/agent-35511965948/aw-ci-scan-feedback-fixer-dedup-headref-listget.bundle refs/heads/ci-scan-feedback-fixer-dedup-headref-listget:refs/bundles/create-pr-ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3-12246dde
git update-ref refs/heads/ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3 refs/bundles/create-pr-ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3-12246dde
git checkout ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3
# Ensure the working tree matches the updated branch
git reset --hard
# Remove the temporary bundle ref
git update-ref -d refs/bundles/create-pr-ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3-12246dde

# Push the branch to origin
git push origin ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3

# Create the pull request
gh pr create --title '[ci-scan-feedback] Read ci-fix head.ref via list/get, not search, to close dedup gap' --base main --head ci-scan-feedback-fixer-dedup-headref-listget-7090a0294c34b8a3 --repo dotnet/runtime