build

name	build
description	Builds project with auto-detected toolchain (npm, poetry, cargo, go, flutter, Docker). Triggers: build, compile, bundle, produce artifacts.
effort	low
disable-model-invocation	true
argument-hint	[target]
allowed-tools	Bash, Read

Build Project

$ARGUMENTS

Build the current project.

Project context

• Project config: !cat package.json 2>/dev/null || cat pyproject.toml 2>/dev/null || echo "unknown"

Auto-Detection

Run the bundled script to detect build system:

python3 ${CLAUDE_SKILL_DIR}/scripts/detect-build.py [dev|prod|docker]

Usage

/build [target]

What This Command Does

1. Detects project type
2. Runs appropriate build command
3. Reports build status

Build Commands by Project Type

Project Type	Build Command
Node.js	npm run build or pnpm build
Python	poetry build or pip install -e .
Flutter	flutter build
Go	go build ./...
Rust	cargo build --release
Docker	docker compose build

Output Format

## Build Report

### Status: Success / Failed

### Build Details
- **Project**: [name]
- **Type**: [type]
- **Command**: [command used]
- **Duration**: [time]

### Artifacts
- [artifact 1]
- [artifact 2]

### Warnings
- [warning if any]

### Errors
- [error if any]

Targets

Target	Description
dev	Development build
prod	Production build
docker	Docker image build
all	Build all targets

MANDATORY: Documentation Update

After build configuration changes, update documentation:

When to Update

• Build config changes -> Update build docs
• New dependencies -> Update requirements docs
• Docker changes -> Update Docker docs
• CI changes -> Update CI/CD docs

Post-Build Changes Checklist

• Build successful
• README build instructions updated (if changed)
• CI/CD config documented

Rules

• MUST detect the build system automatically (detect-build.py) before invoking any command
• NEVER run a clean build when incremental works — clean only on explicit user request
• CRITICAL: surface the first build error literally, including the stack trace and file:line. Paraphrasing loses the diagnostic.
• MANDATORY: on success, report the artifact paths (compiled binaries, bundled output, built images) — callers downstream need them

Gotchas

• npm run build does not refresh node_modules. If package-lock.json is out of sync, the build runs against stale dependencies and "succeeds" with wrong versions. In CI always precede with npm ci.
• cargo build --release takes 5-10× longer than debug. Never use --release in a dev loop; reserve it for CI artifacts and benchmarks.
• docker compose build keys layer cache per service. A change to a shared context file (e.g., root COPY . .) invalidates every service's cache. Structure Dockerfiles to copy dependency manifests first, source last.
• flutter build apk without --split-per-abi produces a fat APK ~3× larger than needed. Production builds should always split unless explicitly bundling.
• go build ./... succeeds with a warning when a package has no Go files (e.g., pure-doc subdir). Downstream tools that expect every listed package to compile a binary fail silently — check go build -v for the list of built packages.

When NOT to Use

• For running tests — use /test
• For deployment or artifact push — use /deploy
• For scaffolding a new build system — use /app-builder or /ci
• For CI pipeline generation — use /ci
• When the project has no build step (interpreted code, pure docs) — this skill has nothing to do