From 0e66764cea4fe700b213ad5622e5f1014c4e5514 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Jare=C5=A1?= <me@jakubjares.com>
Date: Mon, 18 May 2026 16:27:05 +0200
Subject: [PATCH] Fix MsCoverageReferencedPathMaps: skip during design-time
 builds and add BuildInParallel

- Add 'DesignTimeBuild' != 'true' condition to MsCoverageReferencedPathMaps target
  to prevent it from running during IDE design-time builds (fixes #15105).
  Design-time builds are frequent background builds triggered by VS for
  IntelliSense/code analysis, and running MSBuild on all referenced projects
  during each of these builds causes significant IDE slowdowns.

- Add BuildInParallel="true" to the MSBuild task to parallelize the invocation
  across referenced projects, reducing build times for solutions with many
  dependencies (partial fix for #15295).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../Microsoft.CodeCoverage/Microsoft.CodeCoverage.targets      | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/package/Microsoft.CodeCoverage/Microsoft.CodeCoverage.targets b/src/package/Microsoft.CodeCoverage/Microsoft.CodeCoverage.targets
index 0e75c6c723..e68ac1ab04 100644
--- a/src/package/Microsoft.CodeCoverage/Microsoft.CodeCoverage.targets
+++ b/src/package/Microsoft.CodeCoverage/Microsoft.CodeCoverage.targets
@@ -34,10 +34,11 @@
 
   <!-- This target required to store deterministic sources mapping.
        It is modified version of https://github.com/coverlet-coverage/coverlet/blob/d1ca364b7dbff38abce0457d94c4ce1b7e3a4cd9/src/coverlet.collector/build/coverlet.collector.targets#L35 -->
-  <Target Condition="'$(NETCoreSdkVersion)' != '' and '$(DisableMsCoverageReferencedPathMaps)' != 'true'" Name="MsCoverageReferencedPathMaps" BeforeTargets="CoreCompile" DependsOnTargets="ResolveProjectReferences" >
+  <Target Condition="'$(NETCoreSdkVersion)' != '' and '$(DisableMsCoverageReferencedPathMaps)' != 'true' and '$(DesignTimeBuild)' != 'true'" Name="MsCoverageReferencedPathMaps" BeforeTargets="CoreCompile" DependsOnTargets="ResolveProjectReferences" >
     <MSBuild Projects="@(AnnotatedProjects->'%(FullPath)')"
              Targets="$(_msCoverageSourceRootTargetName)"
              Properties="TargetFramework=%(AnnotatedProjects.NearestTargetFramework)"
+             BuildInParallel="true"
              SkipNonexistentTargets="true">
       <Output TaskParameter="TargetOutputs"
               ItemName="_msCoverageLocalTopLevelSourceRoot" />