eval-performance

## MSBuild Evaluation Phases For a comprehensive overview of MSBuild's evaluation and execution model, see [Build process overview](https://learn.microsoft.com/en-us/visualstudio/msbuild/build-process-overview). 1. **Initial properties**: environment variables, global properties, reserved properties 2. **Imports and property evaluation**: process `<Import>`, evaluate `<PropertyGroup>` top-to-bottom 3. **Item definition evaluation**: `<ItemDefinitionGroup>` metadata defaults 4. **Item evaluation**: `<ItemGroup>` with `Include`, `Remove`, `Update`, glob expansion 5. **UsingTask evaluation**: register custom tasks Key insight: evaluation happens BEFORE any targets run. Slow evaluation = slow build start even when nothing needs compiling. ## Diagnosing Evaluation Performance ### Using binlog 1. Replay the binlog: `dotnet msbuild build.binlog -noconlog -fl -flp:v=diag;logfile=full.log` 2. Search for evaluation events: `grep -i 'Evaluation started\|Evaluation finished' full.log` 3. Multiple evaluations for the same project = overbuilding 4. Look for "Project evaluation started/finished" messages and their timestamps ### Using /pp (preprocess) - `dotnet msbuild -pp:full.xml MyProject.csproj` - Shows the fully expanded project with ALL imports inlined - Use to understand: what's imported, import depth, total content volume - Large preprocessed output (>10K lines) = heavy evaluation ### Using /clp:PerformanceSummary - Add to build command for timing breakdown - Shows evaluat...