dart-ci - SKILL.md Agent Skill

name: dart-ci description: "DART CI: GitHub Actions, cache debugging, and platform-specific failures"

DART CI/CD Troubleshooting

Load this skill when debugging CI failures or working with GitHub Actions.

Quick Commands

# Monitor PR checks
gh pr checks <PR_NUMBER>
gh pr checks <PR_NUMBER> --watch --interval 30 --fail-fast

# View run details
gh run list --branch <BRANCH> -e pull_request -L 20
gh run watch <RUN_ID> --interval 30
gh run view <RUN_ID> --json status,conclusion,url

# Debug failures
gh run view <RUN_ID> --job <JOB_ID> --log-failed
gh run view <RUN_ID> --json jobs --jq '.jobs[] | {name, databaseId}'

# Rerun failed jobs only after explicit maintainer/user approval
gh run rerun <RUN_ID> --failed
gh run rerun <RUN_ID> --job <DATABASE_ID>

Full Documentation

For complete CI/CD guide: docs/onboarding/ci-cd.md

Common Failure Modes

Failure Type	Solution
Formatting fails	`pixi run lint`; push only after approval
Codecov patch fails	Add tests for uncovered lines
FreeBSD RTTI fails	Use type enums + `static_cast` instead of `dynamic_cast`
macOS ARM64 SEGFAULT	Replace `alloca()`/VLAs with `std::vector<T>`
RTD build fails	Use defensive `.get(key, default)` patterns
gz-physics fails	Reproduce with `pixi run -e gazebo test-gz`

Workflow Architecture

Workflow	Purpose	Platforms
`ci_lint.yml`	Formatting	Ubuntu
`ci_ubuntu.yml`	Build + test + coverage	Ubuntu
`ci_macos.yml`	Build + test	macOS
`ci_windows.yml`	Build + test	Windows
`ci_freebsd.yml`	Build + test (VM)	FreeBSD
`ci_gz_physics.yml`	Gazebo integration	Ubuntu
`ci_cuda.yml`	CUDA compile + smoke	Ubuntu/GPU

CUDA Runner Policy

The project has a trusted ubuntu-latest-gpu runner for same-repository CUDA runtime validation, but it must never run untrusted fork-PR code. Consequences:

Same-repository PRs, protected branch pushes, and manual dispatches use the GPU runner and run pixi run --locked -e cuda test-cuda.
Fork PRs use a GitHub-hosted fallback and compile CUDA targets without running GPU-only steps.
Local CUDA validation is pixi run -e cuda test-all on Linux hosts with a visible NVIDIA CUDA runtime; local Pixi config auto-detects visible GPU compute capabilities for DART_CUDA_ARCHITECTURES.
pixi run check-phase5-cuda-workflow enforces the trusted-event GPU guard and fork-PR hosted fallback in ci_cuda.yml.

Fast Iteration Loop

Identify failing step from job logs
Reproduce locally with same build toggles
Fix the smallest failing test
Push only after explicit maintainer/user approval, then monitor: gh run watch <RUN_ID>

Caching

sccache/ccache reduces build time 50-70%
Check cache hit rates in workflow logs
Force cache bust by changing cache key if needed

Expected CI Times

Platform	Cached	Uncached
Ubuntu	20-30 min	45-60 min
macOS	15-25 min	30-45 min
Windows	15-20 min	25-35 min