check-bin-obj-clash

SKILL.md

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.