check-bin-obj-clash

# Detecting OutputPath and IntermediateOutputPath Clashes ## Overview This skill helps identify when multiple MSBuild project evaluations share the same `OutputPath` or `IntermediateOutputPath`. This is a common source of build failures including: - File access conflicts during parallel builds - Missing or overwritten output files - Intermittent build failures - "File in use" errors - **NuGet restore errors like `Cannot create a file when that file already exists`** - this strongly indicates multiple projects share the same `IntermediateOutputPath` where `project.assets.json` is written Clashes can occur between: - **Different projects** sharing the same output directory - **Multi-targeting builds** (e.g., `TargetFrameworks=net8.0;net9.0`) where the path doesn't include the target framework - **Multiple solution builds** where the same project is built from different solutions in a single build **Note:** Project instances with `BuildProjectReferences=false` should be **ignored** when analyzing clashes - these are P2P reference resolution builds that only query metadata (via `GetTargetPath`) and do not actually write to output directories. ## When to Use This Skill **Invoke this skill immediately when you see:** - `Cannot create a file when that file already exists` during NuGet restore - `The process cannot access the file because it is being used by another process` - Intermittent build failures that succeed on retry - Missing output files or unexpected overwriting #...