Setup Pr Branch

Set Up a Fork PR Branch for Pushing

The goal is a local branch that (a) tracks the fork's PR branch and (b) can be pushed back to update the PR. Two facts matter:

• GitHub's refs/pull/N/head is read-only; you cannot push to it.
• Maintainers push to a fork PR by pushing to the fork itself. When "allow edits from maintainers" is enabled, GitHub grants the maintainer temporary write access to the fork's PR branch, so the push updates the PR head directly.

So a fork remote must have both its fetch and push URLs pointing at the fork (git@github.com:<owner>/Nuitka.git).

1. Discover the PR head

gh pr view <N> --json headRepositoryOwner,headRefName,baseRefName \
  --jq '{owner: .headRepositoryOwner.login, branch: .headRefName, base: .baseRefName}'

Remember owner and branch. owner is usually the GitHub username, lowercase.

2. Create/repair the fork remote

Use the owner's login as the remote name. If it does not exist yet:

git remote add <owner> git@github.com:<owner>/Nuitka.git

git remote add sets both fetch and push URLs to the fork. If a previous wrong setup left a --push override, restore it to the fork:

git remote set-url --push <owner> git@github.com:<owner>/Nuitka.git

Do not use git remote update <owner> or git fetch <owner> with no refspec: that fetches every branch of the fork.

3. Fetch only the PR branch

git fetch <owner> <branch>

With the default +refs/heads/*:refs/remotes/<owner>/* refspec, this fetches exactly one branch and creates/updates refs/remotes/<owner>/<branch>, nothing else.

4. Check out with tracking

Name the local branch pr-<N> for clarity (the fork's branch name is often generic). This also makes it unambiguous which PR you are on.

git checkout -b pr-<N> --track <owner>/<branch>

If the branch already exists, just fix its upstream instead:

git branch --set-upstream-to=<owner>/<branch> pr-<N>

5. Push back (updates the PR)

git push <owner> HEAD:<branch>

Use git push --force <owner> HEAD:<branch> only after a rebase. GitHub applies these commits to the open PR automatically.

Notes / pitfalls

• gh pr checkout <N> fetches the entire fork; prefer the manual steps above to fetch only the single PR branch.
• A pre-push hook (autoformat) runs git diff <remote>..<local> and can list many files when the local and remote branches have diverged; that is only the check, not the push payload. If the hook itself hangs or is slow, --no-verify skips it, but run the autoformatter yourself first.
• If git status reports the branch "diverged" from <owner>/<branch>, it is usually a stale remote-tracking ref: git fetch <owner> <branch> refreshes it.
• Because the local branch is named pr-<N> while the remote branch keeps the fork's name, a bare git push refuses (push.default=simple requires the names to match). Use git push <owner> HEAD:<branch>, or git config push.default upstream (repo-local) to make bare git push follow the upstream.