---
phase: 13-cicd
plan: 01
subsystem: infra
tags: [github-actions, ci, cross-platform, sapling, pytest]

# Dependency graph
requires:
  - phase: 12-packaging
    provides: pyproject.toml with project configuration
provides:
  - GitHub Actions CI workflow with cross-platform test matrix
  - Automated testing on push/PR to main/master
  - Platform-specific Sapling installation for Linux/macOS/Windows
affects: [documentation, release]

# Tech tracking
tech-stack:
  added: [github-actions, actions/checkout@v4, actions/setup-python@v5]
  patterns: [matrix strategy for cross-platform testing, conditional steps per OS]

key-files:
  created: [.github/workflows/ci.yml]
  modified: []

key-decisions:
  - "Python version matrix: 3.9, 3.11, 3.13 (oldest active, middle, latest)"
  - "fail-fast: false to see all failures across matrix"
  - "Windows sl alias removal in separate step before test run"

patterns-established:
  - "Platform conditionals: Use runner.os for platform detection"
  - "Windows PATH: Use GITHUB_PATH for persistent PATH changes"

# Metrics
duration: 1min
completed: 2026-01-19
---

# Phase 13 Plan 01: CI Workflow Summary

**GitHub Actions CI workflow testing on Ubuntu, macOS, Windows with Python 3.9/3.11/3.13 and platform-specific Sapling installation**

## Performance

- **Duration:** 1 min
- **Started:** 2026-01-19T03:30:08Z
- **Completed:** 2026-01-19T03:31:21Z
- **Tasks:** 3 (combined into 1 cohesive workflow file)
- **Files modified:** 1

## Accomplishments
- CI workflow triggers on push/PR to main/master branches
- 3x3 matrix (3 OS x 3 Python versions = 9 combinations) with fail-fast disabled
- Platform-specific Sapling installation: Ubuntu deb, macOS Homebrew, Windows zip
- Windows PowerShell sl alias conflict handled with Remove-Alias command
- Tests run via project's `python test` script

## Task Commits

Each task was committed atomically:

1. **Tasks 1-3: CI workflow with matrix, Sapling install, test execution** - `0bab332` (feat)

**Plan metadata:** Pending (docs: complete plan)

## Files Created/Modified
- `.github/workflows/ci.yml` - CI test workflow with cross-platform matrix strategy

## Decisions Made
- Python versions 3.9, 3.11, 3.13 selected per research recommendation (oldest active, middle, latest)
- Combined all 3 tasks into single cohesive workflow file since they all modify the same file
- Used `fail-fast: false` to see all failures rather than stopping at first failure
- Windows sl alias removal added as separate step before test run to handle PowerShell session refresh

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None - workflow created successfully, YAML validation passed.

## User Setup Required

None - no external service configuration required. Workflow will automatically run on push/PR once pushed to GitHub.

## Next Phase Readiness
- CI workflow ready, will trigger on next push to main/master
- Release workflow (13-02) can be implemented next
- PyPI trusted publishing configuration will be needed before release workflow can publish

---
*Phase: 13-cicd*
*Completed: 2026-01-19*
