Active rebaser

Rebase every local branch and worktree onto the new main, one at a time, then report and ask which rebased branches to push. Never push anything without explicit per-branch approval, and never push with anything other than --force-with-lease.

Enumerate

git rev-parse --abbrev-ref HEAD          # remember where to return
git branch --format='%(refname:short)'   # every local branch except main
git worktree list --porcelain            # which branch is checked out where

Record each branch's pre-rebase SHA (git rev-parse <branch>) before touching it — that SHA is the undo button.

Skip a branch and mark it up to date when git merge-base --is-ancestor main <branch> succeeds.

Rebase, one branch at a time

• A branch checked out in a worktree is rebased inside that worktree: git -C <worktree-path> rebase main. A dirty worktree is skipped and reported — never stash someone's work-in-progress.
• Any other branch is rebased in the primary worktree with git rebase main <branch> if it is clean, or in a throwaway git worktree add under the scratchpad if it is not. Return to the original branch when the loop ends.

Conflicts: resolve small, abort big

A conflict is simple only when every conflicted file (2 files at most) is one of:

• a lockfile or generated file — regenerate it instead of merging text
• both sides added independent lines to the same list (imports, exports, table rows) — keep the union
• a version or date bump — keep the newer value
• one side is a strict superset of the other — keep the superset

Anything else — overlapping logic edits, a moved function, 3+ conflicted files, or any doubt at all — is huge: git rebase --abort, record the conflicted paths for the report, move to the next branch. Never write new code inside a conflict hunk; resolution picks between what the two sides already wrote.

After any hand-resolved rebase, run bun run system-check on that branch. If it fails, git reset --hard <pre-rebase SHA> and report the branch as restored, with the failing output.

Report

When the loop finishes, show one table — every branch appears, no silent skips:

Branch	Result	Details
foo	rebased clean	3 commits replayed
bar	rebased — conflicts resolved	lockfile regenerated; check pass
baz	aborted — conflict too big	src/data/progress.ts + 4 more
qux	up to date	already contains main

Approval, then push

Ask which successfully rebased branches to push (one multi-select question listing only the rebased ones — aborted and up-to-date branches are not offered). Then, for each approved branch only:

git push --force-with-lease origin <branch>

A --force-with-lease rejection means the remote moved since the last fetch — report it and stop; do not retry with --force.

Common mistakes

Mistake	Consequence
Pushing without asking, or batching approval	The whole point of the report is per-branch consent. Ask first.
--force after a --force-with-lease rejection	Overwrites remote work the lease just protected. Report instead.
"This conflict is only medium-sized"	The simple list is exhaustive. Not on it → abort. There is no medium.
Inventing code to satisfy a conflict hunk	That is authoring changes nobody reviewed. Abort instead.
Stashing a dirty worktree to force the rebase	Someone's WIP is not yours to shelve. Skip and report.
Losing the pre-rebase SHA	No clean undo when system-check fails. Record it before every rebase.