dotnet-msbuild-authoring

To add a custom MSBuild target before CoreCompile, define your target and use the BeforeTargets attribute to execute custom build steps like code generation prior to compilation. This ensures your custom logic integrates seamlessly into the standard .NET SDK build pipeline.

Your MSBuild custom target runs every time because it likely lacks incremental build optimization. By specifying the Inputs and Outputs attributes on your target, MSBuild can compare timestamps and skip execution when outputs are already up to date, significantly speeding up builds.

The correct import order places Directory.Build.props before the SDK targets to set properties, and Directory.Build.targets after to override build behavior. This sequence ensures properties are available during SDK evaluation and targets can modify the finalized build process.

To pass and manipulate item metadata in MSBuild, use item grouping and metadata expressions to attach contextual information to files. You can then batch over these items in your targets, allowing complex build logic to dynamically process distinct groups of files based on their metadata.

You can use property functions and conditions to dynamically control MSBuild behavior by evaluating expressions during the build. Conditions allow skipping targets or properties based on configuration, while property functions enable runtime calculations and string manipulation directly within your project files.

The best way to structure MSBuild configurations for a monorepo is using advanced Directory.Build.props and targets patterns. These files propagate centrally across your repository folders, allowing shared property definitions and custom target overrides without duplicating code in individual project files.