Repair the stack when branches point at stale parent commits. User input: $ARGUMENTS.

When restack is needed

• gt sync reported "could not restack" for one or more branches.
• A PR was squash-merged on GitHub — children still reference the pre-squash SHA.
• A manual git rebase was run on a tracked branch (avoid this in general).
• gt ls shows needs restack next to a branch.

Steps

1. Run gt ls to identify branches marked needs restack.
2. If a specific branch was named in conflict output, gt co <branch> first.
3. Run the appropriate scope:
   • gt restack — restack the current stack on its current parents.
   • gt restack -u / --upstack — only branches above the current one.
   • gt restack -d / --downstack — only branches below the current one.
   • gt restack -o / --only — current branch only, leave neighbors.
4. On conflict during the rebase:
   • Resolve conflicts in editor (markers <<<<<<< / ======= / >>>>>>>).
   • gt add . to mark resolved (wraps git add).
   • gt continue -a to finish the restack chain.
   • Or gt abort to back out — safe to do.
5. After clean restack, run gt ls to confirm and consider gt submit --stack -u to update the PRs.

Notes

• gt restack is idempotent — running it on an already-clean stack is a no-op.
• Across worktrees: run gt restack from each worktree that owns branches in the stack (Graphite 1.8.4+).