Worktrees for parallel nub work

Substantive nub-repo work lands via a PR opened from an isolated git worktree; the shared working tree stays on main and is never branched, reset, or stashed. The whole setup is one command — don't hand-roll the git worktree add + target-dir recipe.

Create a worktree

The script runs under both nub (dogfood) and plain Node:

nub  scripts/new-worktree.ts <slug>
node scripts/new-worktree.ts <slug>

It performs the proven recipe, in order:

1. git fetch origin (skip with --no-fetch).
2. git worktree add ~/.cache/nub/worktrees/<slug> -b <slug> origin/main — tracked files only; the shared tree is untouched. vendor/aube is plain in-tree files, checked out by this step with no submodule init. (Non-temp location: not auto-swept like /tmp, out of the repo dir, same volume so APFS clonefile stays fast.)
3. Apply .worktreeinclude — copy/symlink the listed gitignored entries in.
4. Pre-create + print the shared CARGO_TARGET_DIR (~/.cache/nub/shared-target).

Options: --base <ref> (default origin/main), --path <dir> (default ~/.cache/nub/worktrees/<slug>), --no-fetch, --help.

Then build through the wrapper — do not export CARGO_TARGET_DIR yourself; scripts/rust-build.sh picks the right dir and CoW-seeds an isolated one when this worktree diverges a depended-on crate (see the rust-build skill):

cd ~/.cache/nub/worktrees/<slug>
scripts/rust-build.sh build -p nub-cli --profile fast

All worktrees share ONE target dir (~/.cache/nub/shared-target), so a second worktree reuses the crates.io dependency artifacts another already compiled and recompiles only the ~10 workspace crates — one target dir instead of ~30 multi-GB private ones. Tradeoff: cargo locks the target dir during a build, so two sharing worktrees serialize. Don't clean the shared dir between iterations. Build loop, profiles, and crate map: the dev-loop skill.

.worktreeinclude — bringing gitignored things in

git worktree add checks out tracked files only, so a worktree is lean by default (no target/, node_modules/, .repos/). .worktreeinclude at the repo root lists the gitignored things a worktree still needs; the script copies or symlinks each in.

Format — one entry per line, # comments and blank lines ignored:

[copy|symlink] <path>      # path is relative to the repo root, both sides

The verb is optional and defaults to copy; use symlink for large read-only things. Sources are read from the MAIN working tree even when you run the script from inside another worktree.

The shipped default symlinks .repos/ (read-only reference checkouts of Node, Bun, pnpm, …). Do NOT add target/ — the shared CARGO_TARGET_DIR is the build cache; an in-worktree target/ is exactly the disk bloat the shared dir avoids.

Eagerly pull the shared tree

The shared tree drifts behind origin/main because every landing goes worktree → push → merge and nothing pulls it back. After merging any PR or pushing to origin:

git -C <shared-tree> fetch origin && git -C <shared-tree> merge --ff-only origin/main

Never git pull --ff-only here. This repo sets pull.rebase=true, so pull runs rebase's precondition check first and aborts with cannot pull with rebase: You have unstaged changes on ANY dirty file — and the shared tree always carries some agent's WIP, so that form fails 100% of the time. merge --ff-only has no clean-tree precondition; it refuses only if the incoming commits would overwrite a locally-modified file.

Corollary: do NOT commit directly in the shared tree's checkout — a direct commit makes it diverge rather than merely fall behind, and a diverged tree cannot be fast-forwarded at all. If you take the sanctioned docs/control-surface exception, sync immediately before committing and push in the same breath; never rest with an unpushed commit there. This keeps files current; loaded .claude/ hooks still need a session restart.

Clean up after a merge

git worktree remove ~/.cache/nub/worktrees/<slug> --force   # leave ~/.cache/nub/shared-target in place

--force discards the worktree even with build artifacts present — so push your work first; anything uncommitted is thrown away. Do NOT delete ~/.cache/nub/shared-target — it's the warm cache the next worktree builds against.

Remove ONLY the EXACT worktree path you own — never hunt for one by HEAD SHA. If the stated path does not exist, STOP and report "nothing to clean." Sibling worktrees routinely share a HEAD (two branches cut from the same base, a stacked branch off another's head), so SHA-matching deletes a different agent's active worktree and --force-discards its uncommitted WIP. A dispatch prompt with a cleanup step must name the exact path and add: "remove only this path; if absent, report and stop — never match by SHA."

There is also an older bash helper, scripts/worktree.sh (worktrees under .worktrees/, branched off LOCAL main, with rm/list/reap subcommands and uncommitted/unpushed-work safety checks). new-worktree.ts is the preferred entry for landing work; reach for worktree.sh reap to prune stale dead-session worktrees.