multi-stage-build

{
  "source": "/home/user/project",
  "install_cmd": "pip install -e '.[dev]'",
  "build_cmd": "python -m build",
  "test_cmd": "pytest -v"
}

Execute a multi-stage build with rollback checkpoints:

Source: `/home/user/project`

**Stage 1: Setup Base**
1. Check if `tag:python:3.11-slim` exists, import if needed
2. Sync source files with `rsync`

**Stage 2: Install Dependencies** (checkpoint: `deps-installed`)
1. Run `pip install -e '.[dev]'` with `disposable=false`
2. Save `result_image` as rollback point
3. If this fails, report error and stop

**Stage 3: Build** (checkpoint: `build-complete`)
1. Run `python -m build` on deps image with `disposable=false`
2. Save `result_image` as rollback point
3. If this fails, can rollback to deps-installed image

**Stage 4: Test**
1. Run `pytest -v` on build image (disposable=true for tests)
2. Report test results
3. If tests fail, can rollback to build-complete or deps-installed

**Rollback Strategy:**
- Keep track of each stage's `result_image` UUID
- On failure, report which checkpoint to resume from
- Previous checkpoints remain valid for retry

{
  "prompt": "multi-stage-build",
  "args": {
    "source": "/path/to/package"
  }
}

{
  "prompt": "multi-stage-build",
  "args": {
    "source": "/path/to/project",
    "install_cmd": "pip install poetry && poetry install",
    "build_cmd": "poetry build",
    "test_cmd": "poetry run pytest --cov"
  }
}

{
  "prompt": "multi-stage-build",
  "args": {
    "source": "/path/to/rust-project",
    "install_cmd": "cargo fetch",
    "build_cmd": "cargo build --release",
    "test_cmd": "cargo test"
  }
}

base_image = "tag:python:3.11-slim"
      |
      v
deps_image = run(install_cmd, disposable=false).result_image
      |
      v
build_image = run(build_cmd, image=deps_image, disposable=false).result_image
      |
      v
test_result = run(test_cmd, image=build_image, disposable=true)