---
key: process.branch-off-feature-branch
title: 2026-07-21 — Fix onto an unmerged feature branch by branching off it and FF-pushing (#542)
status: active
since: '2026-07-21'
supersedes: none
superseded-by: none
rule: To fix work on an unmerged feature branch, branch off that branch and land by fast-forward push — and after creating a worktree, drive the first Edit/Read from ITS absolute paths and `git status` it before building.
signals: 'unmerged feature branch · FF-push · path leak · sibling worktree recon · wrong tree edits · "0 new tests" · paths: n/a · issues: #542'
mechanics: '`git worktree add -b <fix-branch> <path> <feature-branch>`; land with a fast-forward push to the feature branch. Never touch a sibling worktree that has the branch checked out (see `process.foreign-worktree-plumbing-merge`).'
---

The path-leak trap, hit on 2026-07-12 (#289 → PR#76): reconnaissance by `Read`ing a *sibling* worktree
leaked that tree's absolute paths into subsequent `Edit`s, so the edits landed there rather than in the
fresh worktree. `dotnet` then built the unchanged tree, and the tell was a build reporting "0 new
tests". A `git status` in the new worktree before the first build catches this in one command.
