avoid-c-drive-on-windows-runner

Avoid hardcoding C:\ drive paths on Windows runners.

What it detects

Workflows that run on GitHub-hosted Windows runners and explicitly set paths on the C:\ drive, such as:

• working-directory: C:\...
• env: TEMP: C:\...
• with: path: C:\...
• defaults.run.working-directory: C:\...

Why it matters

GitHub-hosted Windows runners provision the operating system on a slower C:\ drive and provide a faster, larger temporary D:\ drive. Hardcoding C:\ paths for build outputs, caches, or temporary files increases I/O latency and risks running out of space on the OS disk. Consider using Dev Drive (ReFS with copy-on-write) for even faster build and cache performance.

Suggested action

Use D:\ drive paths, runner.temp, or github.workspace for temporary and working data instead of hardcoding C:\ paths. If available, configure a Dev Drive for build outputs and dependency caches to reduce I/O overhead.

Measurement

Compare job duration and disk I/O before and after moving heavy file operations off C:\. If you adopt Dev Drive, also measure build and cache restore times against the default NTFS layout.

Compatibility

This rule targets GitHub-hosted Windows runners (windows-latest, windows-2022, etc.). Self-hosted runners or custom images may have different disk layouts, so findings may need manual review in those environments.