Retry Worktree Implementation Skill

Continue implementing a plan in an existing git worktree. This skill is used when a previous /autoskillit:implement-worktree session hit context limits before completing.

When to Use

• A previous /autoskillit:implement-worktree session exhausted its context
• The worktree already exists with partial implementation
• User provides both the plan path and the existing worktree path

Arguments

/autoskillit:retry-worktree {plan_path} {worktree_path}

• plan_path — Path to the plan file (relative or absolute)
• worktree_path — Absolute path to the existing worktree directory

Critical Constraints

NEVER:

• Create a new worktree — the worktree already exists
• Re-run worktree setup (e.g. task install-worktree) unless the environment is missing/broken
• Re-explore systems that were already explored (skip Step 2 of implement-worktree)
• Implement in the main working directory (always use the worktree)
• Force push or perform destructive git operations
• Consider implementation complete if ANY test fails
• Blame test failures on "pre-existing issues" — ALL tests must pass
• Re-run tests just to see failures — grep the saved output file instead
• Pipe test output through tail, head, or other truncation commands — tail -N buffers the entire stream and produces no output if the process is killed before EOF
• Default to main as the base branch — always discover it from git's upstream structure or the explicit base-branch store file

ALWAYS:

• Use the provided worktree path (do NOT create a new one)
• Use model: "sonnet" when spawning all subagents via the Task tool
• Start by assessing what has already been implemented
• Continue from where the previous session left off
• Run the project's test suite from the worktree directory
• Rebase onto base branch before completion (ready for squash-and-merge)

Workflow

Step 0: Receive and Validate Arguments

Parse two positional arguments from the prompt:

1. Plan path — verify the plan file exists and read it
2. Worktree path — verify the directory exists and is a git worktree. Check that the development environment is set up (e.g. .venv exists for Python projects)

Path Detection: Use path detection to locate both arguments. Scan all tokens after the skill name for those starting with /, ./, temp/, or .autoskillit/. The first such token is plan_path; the second is worktree_path. Ignore any non-path tokens that appear before them (e.g., extra descriptive text like "use this plan" or "from worktree"). If fewer than two path-like tokens are found, abort with a clear error listing what was missing and the correct format: /autoskillit:retry-worktree <plan_path> <worktree_path>

If the worktree path does not exist:

• Abort with error: "Worktree path does not exist. Use /autoskillit:implement-worktree to create a new worktree."

If the environment is missing or broken:

• Re-create the development environment using the project's configured worktree_setup.command, or: cd {WORKTREE_PATH} && task install-worktree

If worktree_path argument is empty or missing: Abort with error: "Worktree path argument is empty. The implement step must have captured worktree_path before context exhaustion. Check that the implement step's capture block ran before context was exhausted."

This is not a fallback — if worktree_path is empty, the recipe must be inspected to determine why the capture did not complete. A common cause is context exhaustion occurring before the skill reached its Step 6 handoff report.

Step 1: Assess Current State

Discover the base branch from git's upstream tracking (primary) or the explicit base-branch store file written by implement-worktree-no-merge (fallback).

CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)

# Primary: read upstream tracking set by implement-worktree-no-merge
BASE_BRANCH=$(git rev-parse --abbrev-ref @{upstream} 2>/dev/null | sed 's|origin/||')

if [ -z "$BASE_BRANCH" ]; then
    # Fallback: read explicit file store written by implement-worktree-no-merge
    MAIN_GIT_DIR=$(git rev-parse --git-common-dir)
    MAIN_REPO_ROOT=$(dirname "${MAIN_GIT_DIR}")
    STORE_FILE="${MAIN_REPO_ROOT}/.autoskillit/temp/worktrees/${CURRENT_BRANCH}/base-branch"
    BASE_BRANCH=$(cat "${STORE_FILE}" 2>/dev/null)
fi

if [ -z "$BASE_BRANCH" ]; then
    echo "ERROR: Cannot determine base branch from git structure."
    echo "Both the upstream tracking ref and the explicit base-branch file at"
    echo ".autoskillit/temp/worktrees/${CURRENT_BRANCH}/base-branch are missing."
    echo "Ensure the worktree was created by implement-worktree-no-merge,"
    echo "which writes both stores at worktree creation time."
    exit 1
fi

Then assess what has been implemented:

1. Read the plan file to understand the full scope
2. Check what has been implemented so far:
   bashCopy

   git log --oneline $(git merge-base HEAD origin/${BASE_BRANCH})..HEAD
   git diff --stat $(git merge-base HEAD origin/${BASE_BRANCH})..HEAD
   

3. Compare implemented changes against plan phases to determine:
   • Which phases are complete
   • Which phase is partially complete
   • Which phases haven't started

Step 1.5: Initialize Code Index for Worktree

Set the MCP code-index project path to the worktree so code searches operate on the correct files:

mcp__code-index__set_project_path(path="{WORKTREE_PATH}")

This must happen before any code-index searches or Explore subagents.

Step 2: Targeted Exploration (Only If Needed)

Only explore systems related to the remaining phases. Do NOT re-explore already-completed work. Use Explore subagents for:

• Files that will be modified in remaining phases
• Test patterns for remaining changes
• Integration points affected by remaining work

Step 3: Continue Implementation

All commands must run from {WORKTREE_PATH}. Use absolute paths to avoid CWD drift across Bash tool calls.

For each remaining/incomplete phase:

1. Announce phase objective and files to modify
2. Implement changes
3. Run per-phase verification if plan specifies it
4. Commit per phase if possible
5. Report phase completion

Where practical, delegate test updates to subagents to keep main conversation context lean.

Step 4: Final Verification

Run the project's code quality checks and test suite from the worktree.

cd {WORKTREE_PATH} && pre-commit run --all-files
cd {WORKTREE_PATH} && task test-all

If tests fail, fix the issue and re-run.

Step 5: Rebase for Squash-and-Merge

git fetch origin
git rebase origin/${BASE_BRANCH}

If conflicts occur, resolve them, git rebase --continue, then re-run tests. Report rebase status.

Step 6: Completion Report

Output to terminal: worktree path, branch name, base branch ($BASE_BRANCH), status, summary of changes, and next steps (fast-forward merge then clean up). Change directory before removing worktree to prevent deleting the cwd. Always confirm the merge went through before removing worktree. Do not merge until user confirms first!

Then emit these structured output tokens on their own lines so recipe capture blocks can extract them:

worktree_path = ${WORKTREE_PATH}
branch_name = ${CURRENT_BRANCH}

Step 6.5: Reset Code Index to Original Project (REQUIRED)

After worktree cleanup, reset the MCP code-index project path back to the original project directory:

mcp__code-index__set_project_path(path="{ORIGINAL_PROJECT_PATH}")

Failure to do this leaves code-index pointing at a deleted worktree path, breaking all subsequent code searches.

Error Handling

• Worktree environment missing — re-create using the project's configured worktree_setup.command, or: task install-worktree
• Phase fails — report which phase and why, offer to fix/retry, skip (if optional), or abort and clean up
• Tests fail — implementation is NOT complete. Fix the issue. If truly unfixable, report to user and ask for guidance. Do NOT proceed or mark as complete.
• Rebase conflicts — resolve keeping implementation intent intact, re-run full test suite after