fix(ci): build conflict trees from main

[cv]

Summary

Conflict publication now constructs validated GitHub trees from the recorded main tree instead of the stale PR head.
Production requests for #7253 and #6054 shrink from 1,180 and 3,754 entries to 13 and 6 entries.

Related Issue

Follow-up to #7542.

Changes

• Build each GitHub tree from the recorded base SHA and the final tree delta.
• Read deletion entries from the base tree.
• Keep parent blob reuse, final-tree equality, verified commits, and atomic ref updates unchanged.
• Model 100 main-only files and a PR-side deletion in the publisher regression.

Type of Change

• Code change (feature, bug fix, or refactor)
• Code change with doc updates
• Doc only (prose changes, no code sample modifications)
• Doc only (includes code sample changes)

Quality Gates

• Tests added or updated for changed behavior
• Existing tests cover changed behavior — justification:
• Tests not applicable — justification:
• Docs updated for user-facing behavior changes
• Docs not applicable — justification: This changes internal GitHub publication mechanics and no user-facing contract.
• Sensitive paths changed (security, policy, credentials, preflight, onboarding, inference, runner, sandbox, or messaging)
• Sensitive-path review completed or maintainer-approved waiver recorded — reviewer/approval link/justification: Maintainer approved this repair after production run 30193861556 demonstrated the failure. Trust boundaries do not change.
• Non-success, skipped, or missing CI check accepted by maintainer — check name, approval link, and follow-up issue:

Documentation Writer Review

• Documentation writer subagent reviewed the completed changes
• Result: no-docs-needed
• Evidence: The change repairs internal GitHub tree publication. It does not change commands, configuration, output, or supported behavior.
• Agent: Codex Desktop

DGX Station Hardware Evidence

• Tested on DGX Station
• Tested commit:
• Station profile/scenario:
• Result:
• Supporting evidence:

Verification

• PR description includes a Signed-off-by: line and every commit appears as Verified in GitHub
• Normal pre-commit, commit-msg, and pre-push hooks passed, or npm run check:diff passed when hooks were skipped or unavailable
• Targeted behavior tests pass for the current change set, or tests are marked not applicable above — command/result or justification: npx vitest run --project integration test/pr-merge-conflict-fixer.test.ts passed 12/12 after formatting.
• Applicable broad gate passed — npm test for broad runtime/test-harness changes; npm run check for repo-wide validation/coverage changes — command/result: Not applicable to this focused publisher fix.
• Quality Gates section completed with required justifications or waivers
• No secrets, API keys, or credentials committed
• npm run docs builds without warnings (doc changes only)
• Doc pages follow the style guide (doc changes only)
• New doc pages include SPDX header and frontmatter (new pages only)

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Signed-off-by: Carlos Villela cvillela@nvidia.com

Summary by CodeRabbit

• Bug Fixes
  • Improved pull request conflict resolution publishing to correctly reflect files added, modified, or deleted on each branch.
  • Ensured resolved updates are built from the correct base revision, preventing unrelated or outdated files from being included.
  • Improved publication accuracy when the target branch has advanced with additional changes.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 762669cf-e27f-4912-af4c-e59df6c316e0

📥 Commits

Reviewing files that changed from the base of the PR and between dc07773 and 424209c.

📒 Files selected for processing (2)

• test/pr-merge-conflict-fixer.test.ts
• tools/pr-merge-conflict-fixer/publish.mts

---

📝 Walkthrough

Walkthrough

The merge conflict fixer now constructs GitHub trees relative to the PR base SHA. Tests add divergent main history and a PR-only file, then verify the resulting tree payload and entries.

Changes

Base-relative tree publication

Layer / File(s)	Summary
Base-relative tree construction tools/pr-merge-conflict-fixer/publish.mts	Changed-path evaluation, deletion source selection, and the GitHub base_tree now use the PR base SHA.
Divergent publication regression coverage test/pr-merge-conflict-fixer.test.ts	Expanded conflict fixtures and publication assertions cover stale main files, PR-only deletions, and the exact generated tree payload.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• NVIDIA/NemoClaw#7573: Both update createGitHubTree and GitHub tree payload construction.
• NVIDIA/NemoClaw#7576: Both adjust SHA selection in createGitHubTree.

Suggested labels: area: ci

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately captures the main change: building conflict trees from the main branch instead of the PR head.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/fix-conflict-tree-base

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_{Comment @coderabbitai help to get the list of available commands.}

[github-code-quality]

Code Coverage Overview

Languages: TypeScript

TypeScript / code-coverage/plugin

The overall coverage in commit 424209c in the codex/fix-conflict-t... branch remains at 96%, unchanged from commit dc07773 in the main branch.

[github-actions]

PR Review Advisor — Informational

Advisor assessment: Informational / low confidence
Next action: No advisor follow-up needed.
Findings: 0 blockers · 0 warnings · 0 suggestions
Status: PR review advisor failed: PR review advisor SDK execution failed: session: correctness-state-analysis omitted required analysis; turn: correctness-state-analysis: correctness-state-analysis omitted required analysis

Model lanes

• GPT-5.6 Terra (primary): Failed
• Nemotron 3 Ultra (second opinion): Completed · high confidence · 0 blockers · 0 warnings · 0 suggestions

Nemotron output stays in workflow artifacts and does not change the assessment above.

E2E guidance

Advisory only. E2E / PR Gate selects and runs jobs independently.

Recommended E2E: None

Workflow run details

This automated review informs maintainers. Warnings and suggestions do not require a response. A maintainer decides whether to merge.