resolve-conflicts git:20260924.b3c4ba6A

Immutable. This exact content never changes and is served at /api/v1/blob/e017e7b5ccf9f50e.

---
name: resolve-conflicts
description: Resolves merge conflicts on configured-bot PRs and, when requested, upstream dependency-bot PRs.
metadata:
  internal: true
---

# Resolve Conflicts

Resolve configured-bot PRs. Include Dependabot and Renovate only when the
calling skill requests dependency bots.

## Required skills

- Load `/tend-ci-runner:run-tend` before acting.
- Load `/tend-ci-runner:push-commits` before pushing a resolution and `/tend-ci-runner:post-to-github` before composing a deferral comment.
- Load `/tend-ci-runner:monitor-ci` after pushing a conflict resolution.

## Find conflicts

List up to 100 open PRs per author, including the head and base names and SHAs.
Test each PR locally against its own base; GitHub's `mergeable` field can remain
`UNKNOWN` while it computes.

```bash
git fetch --quiet --force origin \
  "refs/heads/<base>:refs/tend/base/<number>" \
  "refs/pull/<number>/head:refs/tend/pr/<number>"
git merge-tree --write-tree \
  "refs/tend/base/<number>" "refs/tend/pr/<number>" >/dev/null
```

Treat a failed query or fetch as unverified, not clean. Remove any prior
conflict-deferral comment from any PR this skill handles that test-merges
clean. When called from `notifications`, use every issue-comment page and skip
a PR whose bot-authored marker names the live `headRefOid`. Nightly ignores the
marker and retries.

When the caller requests dependency bots, include `app/dependabot` and
`app/renovate`.

## Dependency-bot PRs

Read every commit author first — it decides the path.

| Commit authors | Path |
| --- | --- |
| The owning bot alone | Rebuild, per the trigger table. |
| The owning bot plus this bot | Merge and push it yourself, per **Configured-bot PRs**. |
| Anyone else | Leave for manual resolution. |

| PR author | Required commit-author login | Rebuild trigger |
| --- | --- | --- |
| `app/dependabot` | `dependabot[bot]` | Comment `@dependabot recreate`. |
| `app/renovate` | `renovate[bot]` | In the PR body, check `<!-- rebase-check -->`. |

A rebuild overwrites the branch, so it fits only row 1, where the owning bot is
every commit's author. `/tend-ci-runner:review` pushes fixes to dependency-bot PRs by design,
and the owning bot stops resolving conflicts on a branch that has been altered
— leaving a rebuild that would discard the fix as the only trigger, and the PR
wedged at its first conflict. That same commit is what makes the branch this
bot's to merge: resolve it under the exact head lease, as for a configured-bot
PR. Never force-push over a commit from anyone else.

## Configured-bot PRs

Consider dispatching one subagent per conflicted PR. Give each PR an isolated
`$TMPDIR/pr-<number>` worktree.

For each PR:

1. Read and retain `headRefOid`, `headRefName`, `headRepository`, `baseRefName`,
   and `state`. Stop unless the PR is open and its head is in this repository.
   Check out that exact head.
2. Fetch `<baseRefName>` from the remote and pin the SHA that fetch resolves
   to; merge that SHA. Resolve the conflicts, stage them, and commit with
   `git commit --no-edit`. Never merge the PR's `baseRefOid`: it trails the
   base branch, so the merge can succeed without touching the conflict.
3. Immediately before pushing, read those live fields again. If any changed,
   discard the local merge and restart. Verify the retained head is an ancestor
   of `HEAD`, then run `git push
   --force-with-lease="refs/heads/<headRefName>:<headRefOid>" origin
   "HEAD:refs/heads/<headRefName>"`. The exact lease is the final head guard.
4. Fetch the live base again and test the pushed head with `git merge-tree`.
   If it conflicts, merge the new base and repeat. Once clean, remove the bot's
   conflict-deferral comment and monitor CI per `/tend-ci-runner:monitor-ci`.

If resolution is too complex, abort the merge and re-read the PR. When it is
still open at the original head and has no same-head deferral, create one
bot-authored comment that explains manual resolution is needed. Its final line
must be exactly:

```markdown
<!-- tend-conflict-deferred head=<head SHA> -->
```

Find prior deferrals through the paginated issue-comment API. After creating a
comment, re-read the head and comments. Delete only the new comment if the head
changed or an older same-head deferral won a concurrent race. Never edit another
head's deferral. The frequent poll skips the marked head; nightly retries it,
and a new head is eligible immediately.

Remove the temporary worktrees when every PR is done.