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.