Continue PR

Continue Work on a Pull Request

Pick up an existing pull request, resolve conflicts, fix CI failures, address reviewer feedback, and push updates.

Arguments

• $0 (required): PR number in the current repository (e.g., 12345)

Process

1. Parse arguments and fetch PR metadata

Extract the PR number from $0. If not provided, use AskUserQuestion to ask for it.

Validate that the PR number contains only digits. Reject any non-numeric input immediately — do not pass unvalidated input to shell commands or GraphQL queries.

Determine which repository you are operating in — the public ClickHouse/ClickHouse or the private ClickHouse/clickhouse-private:

gh repo view --json nameWithOwner --jq .nameWithOwner   # or: git remote get-url origin

Remember it as $REPO and use it everywhere below instead of the literal ClickHouse/ClickHouse in gh commands, API URLs, and GraphQL repository(owner:, name:) arguments. The repository also decides whom to ask about unrelated CI failures (step 4, item 5): @groeneai in ClickHouse/ClickHouse, @oranjeai in ClickHouse/clickhouse-private.

Fetch PR metadata using gh if available, otherwise use WebFetch on the GitHub API:

gh pr view "$PR_NUMBER" --json number,title,body,headRefName,baseRefName,state,mergeable,mergeStateStatus,author,url,headRepository,headRepositoryOwner,statusCheckRollup,reviews,comments,reviewRequests

If gh is not available or not authenticated, use WebFetch to get the data. Append ?per_page=100 and follow the Link header for pagination (the rel="next" URL) to fetch all pages:

• https://api.github.com/repos/ClickHouse/ClickHouse/pulls/$PR_NUMBER
• https://api.github.com/repos/ClickHouse/ClickHouse/pulls/$PR_NUMBER/reviews?per_page=100
• https://api.github.com/repos/ClickHouse/ClickHouse/pulls/$PR_NUMBER/comments?per_page=100

Report the PR title, author, branch, and current state to the user.

1a. Verify "already integrated" claims before closing

Treat closing a PR as already integrated or obsolete as a high-confidence decision. Verify both of these independently against freshly fetched refs:

1. Historical ancestry: Resolve and print the exact base and PR-head OIDs, then check the candidate commit in this direction only:

   HEAD_REMOTE=origin
   if [ "$IS_CROSS_REPOSITORY" = "true" ]; then
       HEAD_REMOTE="pr-$AUTHOR_LOGIN"
       git remote add "$HEAD_REMOTE" "$FORK_URL" 2>/dev/null || git remote set-url "$HEAD_REMOTE" "$FORK_URL"
   fi
   git fetch origin "$BASE_BRANCH"
   git fetch "$HEAD_REMOTE" "$HEAD_BRANCH"
   git rev-parse "origin/$BASE_BRANCH" "$HEAD_REMOTE/$HEAD_BRANCH"
   git merge-base --is-ancestor "$CANDIDATE_COMMIT" "origin/$BASE_BRANCH"

   Derive $IS_CROSS_REPOSITORY, $AUTHOR_LOGIN, and $FORK_URL from the PR metadata as in step 2. Exit status 0 means the base contains the commit; any other status means it does not. Never check against HEAD, the PR branch, --all, or a worktree and describe that result as containment by the base branch. If this check is nonzero, do not claim the commit is in the base and do not close the PR as integrated.
2. Current effective state: An ancestor commit may have been reverted or backed out later. Ancestry, git branch --contains, git cherry, and patch-equivalence results are historical evidence only; none proves that the change remains effective. Inspect all later base-branch commits touching the changed paths, search for explicit and manual reverts/backouts, compare the current base tree with the PR's intended effect, and run the reproducer or regression test against the current base when feasible. If the change was fully or partially reverted, count it as not integrated. If the current effect cannot be established confidently, leave the PR open for human review.

Before posting a closure comment, state the fetched base OID and the evidence for both ancestry and the current effective state. Do not close from a remembered ref, a stale local branch, a matching subject, or a commit merely visible somewhere in the repository.

2. Check out the PR branch locally

Before checking out the PR, require a clean worktree. This interactive skill can run in a developer's normal checkout, so it must fail closed rather than discarding staged, unstaged, or untracked work:

test -z "$(git status --porcelain)" || {
    echo "The worktree is dirty; use a clean worktree before continuing this PR" >&2
    exit 1
}

Determine whether the PR branch is in the main repository or in the author's fork.

If the branch is in the main repository (ClickHouse/ClickHouse):

HEAD_REMOTE=origin
git fetch "$HEAD_REMOTE" "$HEAD_BRANCH"
git checkout --detach "$HEAD_REMOTE/$HEAD_BRANCH"

If the branch is in the author's fork:

Derive the fork clone URL from the PR metadata (headRepository.url or headRepository.owner.login + headRepository.name) rather than hardcoding the repository name (forks can be renamed). Use a pr- prefixed remote name to avoid colliding with existing remotes like origin:

REMOTE_NAME="pr-$AUTHOR_LOGIN"
FORK_URL="https://github.com/$FORK_OWNER/$FORK_REPO.git"  # from headRepository in PR metadata
git remote add "$REMOTE_NAME" "$FORK_URL" 2>/dev/null || git remote set-url "$REMOTE_NAME" "$FORK_URL"
HEAD_REMOTE="$REMOTE_NAME"
git fetch "$HEAD_REMOTE" "$HEAD_BRANCH"
git checkout --detach "$HEAD_REMOTE/$HEAD_BRANCH"

After the clean checkout, record the immutable baseline; it is the only authoritative record of the PR surface that existed when the worker began:

git fetch origin "$BASE_BRANCH"
mkdir -p tmp
PR_BASELINE_DIR="$(pwd)/tmp/continue-pr-${PR_NUMBER}-baseline"
rm -rf "$PR_BASELINE_DIR"
mkdir -p "$PR_BASELINE_DIR"
INITIAL_PR_HEAD=$(git rev-parse "$HEAD_REMOTE/$HEAD_BRANCH")
test "$(git rev-parse HEAD)" = "$INITIAL_PR_HEAD"
INITIAL_BASE_HEAD=$(git rev-parse "origin/$BASE_BRANCH")
printf '%s\n%s\n' "$INITIAL_PR_HEAD" "$INITIAL_BASE_HEAD" > "$PR_BASELINE_DIR/state"
git diff --name-status "origin/$BASE_BRANCH"...HEAD > "$PR_BASELINE_DIR/name-status"
git diff --stat "origin/$BASE_BRANCH"...HEAD > "$PR_BASELINE_DIR/stat"
git diff --binary "origin/$BASE_BRANCH"...HEAD > "$PR_BASELINE_DIR/diff"

Do not modify, stage, or delete this artifact during the session. It must remain available through the push safety gate in step 7. The deterministic path and state file are required because each resumed worker turn starts a fresh shell process.

3. Resolve conflicts with the base branch (if any)

Use the PR's actual base branch from metadata (baseRefName) instead of hardcoding master — this ensures backport PRs targeting other branches are handled correctly.

Check if the PR has conflicts with the base branch:

git fetch origin "$BASE_BRANCH"
git merge-base --is-ancestor "origin/$BASE_BRANCH" HEAD || echo "needs merge"

If the branch is behind the base branch and is red (some checks didn't pass), or if it is behind the base branch for more than a week (regardless of checks success), or has conflicts, or the merge queue removed the PR after its last commit (see step 4), merge:

git merge "origin/$BASE_BRANCH"

If there are merge conflicts:

1. List conflicted files: git diff --name-only --diff-filter=U
2. For each conflicted file, use a Task agent with subagent_type=general-purpose to resolve:
   • Read the conflicted file
   • Analyze conflict markers
   • Resolve intelligently: the PR's changes should generally take precedence for the code the PR modifies, while master's changes take precedence for unrelated areas
   • Stage the resolved file: git add <file>
   • If conflicts are ambiguous, show them to the user using AskUserQuestion
3. Complete the merge: git commit --no-edit

4. Analyze CI status and fix failures

First, check whether the merge queue rejected the PR. The PR's own CI runs on its head commit, but the merge queue re-tests the PR merged with the latest base branch (a gh-readonly-queue/<base>/pr-<N>-<base-sha> ref, workflow MergeQueueCI). A PR can therefore be all green and CLEAN yet keep being rejected - typically a semantic conflict: a test added on the base branch that pins behaviour this PR changes, or an API the PR uses that was changed on the base branch. Look for the latest merge-queue event:

gh api graphql -f query="
{
  repository(owner: \"${REPO%%/*}\", name: \"${REPO#*/}\") {
    pullRequest(number: $PR_NUMBER) {
      mergeQueueEntry { state }
      commits(last: 1) { nodes { commit { oid committedDate } } }
      timelineItems(last: 1, itemTypes: [ADDED_TO_MERGE_QUEUE_EVENT, REMOVED_FROM_MERGE_QUEUE_EVENT]) {
        nodes { __typename ... on RemovedFromMergeQueueEvent { createdAt reason beforeCommit { oid } } }
      }
    }
  }
}"

If the last event is a RemovedFromMergeQueueEvent (with a reason other than merged) newer than the last commit, and the PR is not back in the queue, the rejection is the first failure to fix. beforeCommit.oid is the merge-queue commit that was tested. fetch_ci_report.js with the PR URL detects this case and adds the failed jobs of that merge-queue run to its output (marked with a ⚠️ line and listed under MergeQueueCI). To look at the run directly, take its report links from the commit statuses (the check runs link to GitHub Actions jobs instead):

MQ_SHA=<beforeCommit.oid>
gh api "repos/$REPO/commits/$MQ_SHA/statuses" --paginate \
    --jq '.[] | select(.state != "success") | "\(.context)\t\(.state)\t\(.target_url)"'
node .claude/tools/fetch_ci_report.js "<a praktika.html?REF=gh-readonly-queue/...&sha=$MQ_SHA&name_0=MergeQueueCI&name_1=<job> URL from above>" --failed

The per-job JSON is also directly at https://s3.amazonaws.com/clickhouse-test-reports/REFs/gh-readonly-queue/<base>/pr-<N>-<base-sha>/$MQ_SHA/mergequeueci/result_<job>.json (gzip-compressed). Do not construct artifact URLs such as log paths by hand: Praktika stores attached files under normalized sub-result directories (e.g. .../mergequeueci/build_amd_binary/build_clickhouse/build_clickhouse.log), so guessed paths return AccessDenied. Follow the links of the failed results in that JSON instead, as printed by fetch_ci_report.js (also with --links), or use --download-logs. To fix the rejection, merge the latest base branch (step 3) even if the PR is otherwise current, reproduce the failure on the merged tree, and fix it in the PR - adapt the code to the changed API, or update a newly added test when the PR intentionally changes the behaviour it pins (say so in the commit message and the PR comment). Do not re-add the PR to the merge queue yourself, and do not dismiss a merge-queue failure as flaky without the same evidence as for any other failure.

Then fetch the PR's own CI reports:

node .claude/tools/fetch_ci_report.js "https://github.com/ClickHouse/ClickHouse/pull/$PR_NUMBER" --failed --cidb

For each CI failure:

1. Check if it is a known issue: Search for existing open issues or PRs that address this failure:

   gh issue list --repo ClickHouse/ClickHouse --state open --search "<failure_description>" --limit 5
   gh pr list --repo ClickHouse/ClickHouse --state open --search "<failure_description>" --limit 5

   Only dismiss a failure as unrelated if there is a concrete open issue or PR that matches. Do NOT dismiss failures without evidence.

2. Investigate the failure: Download logs if needed:

   node .claude/tools/fetch_ci_report.js "<report_url>" --failed --download-logs

   Extract and analyze the relevant logs. Read the failing test files and the code they exercise.

3. Fix the failure: Make the necessary code or test changes. Each fix should be a separate commit with a clear message explaining what was wrong and why.

4. If the only failure is "CH Inc sync", fix it using the /fix-sync skill.

5. If you are confident that the failure is unrelated to the changes, post a comment, asking the reviewer for $REPO (step 1) — @groeneai in ClickHouse/ClickHouse, @oranjeai in ClickHouse/clickhouse-private — to investigate the failure: 🕵 @<reviewer>, investigate the failure: <link> and provide a fix in a separate PR. If the fix is already in progress, link it here.

6. Repeat until all failures are addressed or confirmed as known issues with links to open issues/PRs.