[ci-scan-feedback] Fix fixer dedup: resolve head.ref via list tools, not search #132967

Triggering signals

• [ci-scan-feedback] Read ci-fix head.ref via list/get, not search, to close dedup gap #132616 — a prior [ci-scan-feedback] PR that recorded this exact fix but whose git push failed, so the fix never landed; the issue body preserves the full rationale. [ci-scan-feedback] Read ci-fix head.ref via list/get, not search, to close dedup gap #132616
• [ci-fix] Needs review: select gen-debug-dump-docs Helix post-command shell by WindowsShell (refs #131382) #131981 — help-wanted [ci-fix] PR closed unmerged by kotlarmilos (MEMBER) on 2026-08-14: "Duplicate [ci-fix] Stop dump-doc collection on unsupported Helix targets (refs #131382) #131515." Both PRs target KBE [ci-scan] Build break: Windows Helix work items fail on unexpanded $HELIX_PYTHONPATH in gen-debug-dump-docs post-command #131382 with the same WindowsShell fix on branch ci-fix/131382-...; [ci-fix] Stop dump-doc collection on unsupported Helix targets (refs #131382) #131515 was already open when [ci-fix] Needs review: select gen-debug-dump-docs Helix post-command shell by WindowsShell (refs #131382) #131981 was filed. The Step 3 branch-prefix dedup should have caught it. [ci-fix] Needs review: select gen-debug-dump-docs Helix post-command shell by WindowsShell (refs #131382) #131981 (comment)
• Rubric finding: .github/workflows/ci-failure-fix.md:164 instructs the fixer to parse head.ref from [ci-fix] PRs enumerated via search_pull_requests, but the github MCP search_pull_requests tool schema has no head field and never returns head.ref, so the deterministic branch-prefix dedup key added by Dedup ci-fix PRs by KBE branch prefix #132541 is invisible to search alone.

Proposed edits

• .github/workflows/ci-failure-fix.md:164 — Step 3 enumeration: stop parsing head.ref from search results. Resolve the branch key with the non-search tools — list_pull_requests (state: open, fields incl. head) for open candidates, pull_request_read get for specific merged/closed candidates, and a non-integrity-gated list_branches backstop to enumerate every live ci-fix/<kbe>-... branch prefix.
• .github/workflows/ci-failure-fix.md:166 — Step 3 check 1: clarify that an empty branch map means "not yet enumerated", NOT "no open PR", so the fixer enumerates head branches via list_pull_requests/list_branches before concluding none exists.

Expected behavior change

The next fixer run obtains each candidate [ci-fix] PR's head.ref from list_pull_requests/list_branches (which do expose branches) instead of a search_pull_requests field that is always absent, and treats an unpopulated branch map as "not yet enumerated" rather than "no open PR." This closes the residual self-dedup gap that let help-wanted PR #131981 be filed against KBE #131382 while #131515 was already open on ci-fix/131382-: the fixer will detect the live branch and skip with open fix PR #<n> already exists instead of opening a duplicate.

Generated by CI Outer-Loop Failure Scanner — Feedback · opus48 · 280.5 AIC · ⌖ 25.7 AIC · ⊞ 20.6K · ◷

To create a pull request with the changes:

# Download the artifact from the workflow run
gh run download 33394234113 -n agent -D /tmp/agent-33394234113

# Fetch the bundle into a temporary ref, then update the local branch
git fetch /tmp/agent-33394234113/aw-ci-scan-feedback-fixer-dedup-headref.bundle refs/heads/ci-scan-feedback-fixer-dedup-headref:refs/bundles/create-pr-ci-scan-feedback-fixer-dedup-headref-13d139b40ed0bbf2-50a2e321
git update-ref refs/heads/ci-scan-feedback-fixer-dedup-headref-13d139b40ed0bbf2 refs/bundles/create-pr-ci-scan-feedback-fixer-dedup-headref-13d139b40ed0bbf2-50a2e321
git checkout ci-scan-feedback-fixer-dedup-headref-13d139b40ed0bbf2
# 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-13d139b40ed0bbf2-50a2e321

# Push the branch to origin
git push origin ci-scan-feedback-fixer-dedup-headref-13d139b40ed0bbf2

# Create the pull request
gh pr create --title '[ci-scan-feedback] Fix fixer dedup: resolve head.ref via list tools, not search' --base main --head ci-scan-feedback-fixer-dedup-headref-13d139b40ed0bbf2 --repo dotnet/runtime