Fix CH Inc Sync Skill

Fix the "CH Inc sync" CI job for a ClickHouse pull request by resolving merge conflicts in the corresponding clickhouse-private sync PR.

Arguments

• $0 (required): PR number or full GitHub URL of the public ClickHouse PR (e.g., 96005 or https://github.com/ClickHouse/ClickHouse/pull/96005)

Overview

When a PR is opened in ClickHouse/ClickHouse, a sync PR is automatically created in ClickHouse/clickhouse-private on a branch named sync-upstream/pr/<PR_NUMBER>. If this sync PR has merge conflicts, the "CH Inc sync" check stays pending. This skill resolves those conflicts.

Process

1. Parse the PR number

• Extract the PR number from $ARGUMENTS
• If a full URL is provided (e.g., https://github.com/ClickHouse/ClickHouse/pull/96005), extract the number from the URL
• If no argument is provided, use AskUserQuestion to ask for the PR number

2. Find the sync PR

• Search for the corresponding sync PR in the private repository:

  gh pr list --repo ClickHouse/clickhouse-private --head sync-upstream/pr/<PR_NUMBER> --json number,url,state,mergeable,mergeStateStatus,headRefName
  

• If no sync PR is found, report this to the user and stop
• If the sync PR is not conflicting (mergeable is not CONFLICTING), report that no action is needed and stop
• Report the sync PR number and URL to the user

3. Locate the private repository

• Look for the clickhouse-private repository in common locations relative to the current working directory:
  • ../ClickHouse_private
  • ../clickhouse-private
  • Check if the directory exists and contains a git repository with ClickHouse/clickhouse-private as a remote
• If not found, use AskUserQuestion to ask the user for the path
• Store the path for use in subsequent steps

4. Fetch and switch to the sync branch

In the private repository directory:

cd <private_repo_path> && git fetch origin && git fetch origin sync-upstream/pr/<PR_NUMBER>

Then check out the sync branch:

cd <private_repo_path> && git checkout sync-upstream/pr/<PR_NUMBER>

If the branch has local changes, ask the user before proceeding.

5. Merge master and resolve conflicts

cd <private_repo_path> && git merge origin/master

This will likely produce conflicts. Handle them:

1. List conflicted files:

   cd <private_repo_path> && 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 content
   • Analyze the conflict markers (<<<<<<<, =======, >>>>>>>)
   • Determine the correct resolution:
     • For most sync conflicts, the upstream (public repo) changes should take precedence
     • For files that exist only in the private repo, preserve them
     • For CI/workflow files, be careful to preserve private-repo-specific configurations
   • Apply the resolution using Edit tool
   • Stage the resolved file: git add <file>

   IMPORTANT: If conflicts are complex or ambiguous, show the conflicts to the user and ask how to resolve them using AskUserQuestion.

3. After resolving all conflicts, complete the merge:

   cd <private_repo_path> && git commit --no-edit
   

6. Update submodules (if needed)

cd <private_repo_path> && git submodule update --init --recursive

If submodule update fails, report the error but continue.

7. Build verification (optional)

Use AskUserQuestion to ask the user:

• "Do you want to build ClickHouse in the private repository to verify the merge?"
  • Option 1: "Yes, build" - Run ninja in the private repo build directory
  • Option 2: "No, skip build" - Skip building and proceed to push

If the user chooses to build, use the build skill or run ninja directly.

8. Push the resolved branch

cd <private_repo_path> && git push origin sync-upstream/pr/<PR_NUMBER>

9. Verify the sync PR

After pushing:

gh pr view <SYNC_PR_NUMBER> --repo ClickHouse/clickhouse-private --json mergeable,mergeStateStatus

Report the result:

• If mergeable is MERGEABLE: "Sync PR is now mergeable. The CH Inc sync check should pass shortly."
• If still conflicting: "Sync PR still has conflicts. Additional investigation may be needed."

Provide the sync PR URL for the user to check.

Examples

• /fix-sync 96005 - Fix sync for PR #96005
• /fix-sync https://github.com/ClickHouse/ClickHouse/pull/96005 - Fix sync using full URL

Notes

• The sync branch name follows the pattern: sync-upstream/pr/<PR_NUMBER>
• The private repository is typically located one directory level up from the public repository
• Most conflicts are straightforward and involve the upstream changes taking precedence
• Always fetch before switching branches to ensure you have the latest state
• Do not use rebase or amend - add new commits instead (per project conventions)
• After pushing, it may take a few minutes for the GitHub check to update