From 1d28c66a48cfab488f6d3fe00a8f1cc870f154f9 Mon Sep 17 00:00:00 2001
From: Kieron Lanning <kieronlanning@users.noreply.github.com>
Date: Wed, 16 Sep 2026 18:59:24 +0100
Subject: [PATCH] fix: make benchmark host builds resolve the generator
 correctly

---
 benchmarks/Directory.Build.props              | 12 ++++++++++++
 .../Purview.Telemetry.Benchmarks.csproj       | 19 +++++++++++++++++++
 src/Directory.Build.props                     |  8 ++++++++
 3 files changed, 39 insertions(+)
 create mode 100644 benchmarks/Directory.Build.props

diff --git a/benchmarks/Directory.Build.props b/benchmarks/Directory.Build.props
new file mode 100644
index 00000000..d9c6fbbc
--- /dev/null
+++ b/benchmarks/Directory.Build.props
@@ -0,0 +1,12 @@
+<Project>
+	<PropertyGroup>
+		<!--
+			Keep intermediates in obj/ even when a global ArtifactsPath is supplied
+			(e.g. BenchmarkDotNet's autogenerated host build passes ArtifactsPath/OutDir
+			as global properties). Otherwise the artifacts layout relocates obj/ outside
+			DefaultItemExcludes and emitted generator files get globbed into <Compile>,
+			causing duplicate-symbol errors during host builds.
+		-->
+		<UseArtifactsOutput>false</UseArtifactsOutput>
+	</PropertyGroup>
+</Project>
diff --git a/benchmarks/Purview.Telemetry.Benchmarks/Purview.Telemetry.Benchmarks.csproj b/benchmarks/Purview.Telemetry.Benchmarks/Purview.Telemetry.Benchmarks.csproj
index 8f49edbf..169ec3c0 100644
--- a/benchmarks/Purview.Telemetry.Benchmarks/Purview.Telemetry.Benchmarks.csproj
+++ b/benchmarks/Purview.Telemetry.Benchmarks/Purview.Telemetry.Benchmarks.csproj
@@ -13,13 +13,32 @@
 	</PropertyGroup>
 
 	<ItemGroup>
+		<!--
+			BenchmarkDotNet's autogenerated host build passes ArtifactsPath/OutDir/OutputPath
+			as global properties. Without stripping them here they propagate to the generator
+			project, relocating its build output (relative to the project) into stray folders;
+			the analyzer then cannot load its Purview.SourceGeneratorFramework runtime
+			dependencies from that location. Keep the generator at its normal output path.
+		-->
 		<ProjectReference
 			Include="..\..\src\src\SourceGenerator\SourceGenerator.csproj"
 			OutputItemType="Analyzer"
 			ReferenceOutputAssembly="false"
+			GlobalPropertiesToRemove="ArtifactsPath;OutDir;OutputPath"
 		/>
 	</ItemGroup>
 
+	<ItemGroup>
+		<!--
+			The host build runs with UseSharedCompilation=false, where Roslyn's in-process
+			analyzer loader does not probe the generator's output directory for its runtime
+			dependencies. Load the Purview.SourceGeneratorFramework assemblies as analyzers
+			so they are present in the analyzer load context for every build mode.
+		-->
+		<Analyzer Include="..\..\src\src\SourceGenerator\bin\$(Configuration)\netstandard2.0\Purview.SourceGeneratorFramework.dll" />
+		<Analyzer Include="..\..\src\src\SourceGenerator\bin\$(Configuration)\netstandard2.0\Purview.SourceGeneratorFramework.Shared.dll" />
+	</ItemGroup>
+
 	<ItemGroup>
 		<PackageReference Include="BenchmarkDotNet" Version="0.15.8" />
 		<PackageReference Include="Microsoft.Extensions.Logging" Version="10.0.4" />
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 5d3a1ffe..67a1dbd9 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -6,6 +6,14 @@
 			telemetry... obviously we don't want that here!	
 		-->
 		<ExcludePurviewTelemetry>true</ExcludePurviewTelemetry>
+		<!--
+			Keep intermediates in obj/ even when a global ArtifactsPath is supplied
+			(e.g. BenchmarkDotNet's autogenerated host build passes ArtifactsPath/OutDir
+			as global properties). Otherwise the artifacts layout relocates obj/ outside
+			DefaultItemExcludes and emitted generator files get globbed into <Compile>,
+			causing duplicate-symbol errors during host builds.
+		-->
+		<UseArtifactsOutput>false</UseArtifactsOutput>
 	</PropertyGroup>
 
 	<Import Sdk="Purview.DotNetProjectSdk" Project="Sdk.props" />