git fetch origin main:main refuses if main is checked out in ANY worktree

git fetch origin main:main is the usual way to fast-forward a local branch without checking it out (it also refuses non-fast-forward updates). On git 2.43.0 it fails with fatal: refusing to fetch into branch 'refs/heads/main' checked out at '<path>' (rc=128) not only when you're on main, but also when main is checked out in another linked worktree, while you sit on a feature branch in this one. In multi-worktree setups, update that worktree with git -C <path> merge --ff-only origin/main after a plain git fetch, or use git push origin HEAD:main + fetch. Note that git update-ref bypasses the check and leaves the other worktree's index looking like a reversal.