What problem does it solve? MSBuild item groups are a common source of build bugs: duplicate file warnings from SDK globbing, targets running more times than expected due to cross-product batching, and Include vs Update misuse that silently breaks builds. This Skill provides canonical patterns from Microsoft.Common.CurrentVersion.targets to diagnose and correct these anti-patterns in .csproj files. ## Core Features & Use Cases - Include/Remove/Update Semantics: Clarifies when to add items, subtract items, or modify metadata on existing items without re-adding them. - Batching and Transforms: Explains %(Metadata) batching at target and task level, @(Item->'expression') transforms, and per-item filtering with Condition. - Pitfall Diagnosis: Covers cross-product batching, generated files polluting the source tree, and missing FileWrites registration that breaks dotnet clean. - Use Case: A build logs CS2002 duplicate file warnings after SDK globbing picks up generated files. Use this Skill to move generation to IntermediateOutputPath and apply Remove/Update correctly instead of re-including items. ## Quick Start Review my .csproj file and fix the item group that causes duplicate Compile items and a target running once per configuration instead of once total.
