narumiruna/syncing-main-branch

Syncing Main Branch

Use this skill only after explicit invocation. Switch to main, update it without creating a merge commit, and preserve the branch, commits, and local files being left.

Workflow

1. Inspect before mutating:

   git status --porcelain=v1 --untracked-files=all
   git status --short --branch
   git symbolic-ref --quiet --short HEAD
   

   Stop if tracked or untracked changes exist. Report them; do not stash, commit, discard, or carry them onto main automatically.

   If the symbolic-ref check fails, record git rev-parse HEAD and inspect containing refs with git for-each-ref --format='%(refname)' --contains=HEAD refs/heads refs/tags refs/remotes, then stop. Do not leave a detached commit reachable only through reflog; ask whether to preserve it with a branch or tag before switching.

2. Resolve main.

   • If refs/heads/main exists locally, use it.
   • If local main is absent and exactly one intended remote-tracking main is clear from repository context, create it with git switch --no-overwrite-ignore --track -c main <remote>/main.
   • If the remote is ambiguous, main does not exist, or another worktree already has it checked out, stop and report the specific blocker. Do not substitute master, bypass worktree protection, or invent a remote.

3. Switch when not already on main, protecting ignored local files from branch collisions:

   git switch --no-overwrite-ignore main
   

4. Verify that main tracks the intended <remote>/main. Fetch that remote without updating the worktree, then fast-forward with ignored-file overwrite protection:

   upstream_remote=$(git config --get branch.main.remote)
   git rev-parse --abbrev-ref 'main@{upstream}'
   git fetch "$upstream_remote"
   git merge --ff-only --no-overwrite-ignore 'main@{upstream}'
   

   If the branch has diverged, the upstream is missing or unexpected, authentication fails, an ignored path would be overwritten, or the update cannot fast-forward, stop. Do not rebase, reset, force, delete ignored files, or change upstream configuration without a separate request.

5. Verify and report:

   git status --short --branch
   git log -1 --oneline --decorate
   

   Confirm the active branch, whether it advanced, and whether it matches its upstream. Do not delete the previous feature branch.

Safety Rules

• Operate on the current repository only.
• Require tracked and untracked state to be clean; leave ignored files untouched and use overwrite-protected switch and merge commands.
• Never use interactive Git commands or a pager.
• Never use --force, automatic stashing, hard reset, or branch deletion.
• If the protected fast-forward reports no changes, treat that as success and do not create a commit.