From c74419b333423cc0cefeeb5a16c04a965fbca019 Mon Sep 17 00:00:00 2001
From: Milos Kotlar <kotlarmilos@gmail.com>
Date: Thu, 16 Apr 2026 10:19:16 +0200
Subject: [PATCH 1/2] Fix trimmed library test assemblies missing from app
 bundles

PR #125673 changed Microsoft.NET.ILLink.targets to skip creating the
TrimmerRootAssembly item for Library-output projects. The
RootEntireIntermediateAssembly target in tests.mobile.targets relied on
that item existing so it could update its RootMode metadata from
EntryPoint to 'all'. Since the item no longer exists for Library
projects, the metadata update is a no-op and the test assembly is left
unrooted. ILLink then trims it entirely, causing all Release library
tests on tvOS (both CoreCLR and Mono) to fail with:
  'Test libs were not found (*.Tests.dll was not found in ...)'

Fix by using Remove+Include to unconditionally create the
TrimmerRootAssembly item with RootMode='all', regardless of whether
the SDK already created one.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 eng/testing/tests.mobile.targets | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/eng/testing/tests.mobile.targets b/eng/testing/tests.mobile.targets
index 21b85c60da72e3..f460de543a65fc 100644
--- a/eng/testing/tests.mobile.targets
+++ b/eng/testing/tests.mobile.targets
@@ -46,13 +46,13 @@
   </PropertyGroup>
 
   <!-- When trimming non-exe projects, root the whole intermediate assembly.
-       The SDK settings root only the entry point by default. These targets are used not only for standard
-       console apps, but also for test projects without an entry point. -->
+       The SDK no longer creates a TrimmerRootAssembly item for Library projects (see
+       Microsoft.NET.ILLink.targets), so update the metadata if the item exists and
+       add it outright when it does not. -->
   <Target Name="RootEntireIntermediateAssembly" AfterTargets="PrepareForILLink" Condition="'$(OutputType)' != 'Exe'">
     <ItemGroup>
-      <TrimmerRootAssembly Condition="'%(Identity)' == '$(AssemblyName)'">
-        <RootMode>all</RootMode>
-      </TrimmerRootAssembly>
+      <TrimmerRootAssembly Remove="@(IntermediateAssembly->'%(Filename)')" />
+      <TrimmerRootAssembly Include="@(IntermediateAssembly->'%(Filename)')" RootMode="all" />
     </ItemGroup>
   </Target>
 

From 2f0e54ee3e890213d550496a0d784b2b0da9ba56 Mon Sep 17 00:00:00 2001
From: Milos Kotlar <kotlarmilos@gmail.com>
Date: Fri, 17 Apr 2026 08:52:05 +0200
Subject: [PATCH 2/2] Address review: reword RootEntireIntermediateAssembly
 comment

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 eng/testing/tests.mobile.targets | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/eng/testing/tests.mobile.targets b/eng/testing/tests.mobile.targets
index f460de543a65fc..d38673115d6aa4 100644
--- a/eng/testing/tests.mobile.targets
+++ b/eng/testing/tests.mobile.targets
@@ -47,8 +47,8 @@
 
   <!-- When trimming non-exe projects, root the whole intermediate assembly.
        The SDK no longer creates a TrimmerRootAssembly item for Library projects (see
-       Microsoft.NET.ILLink.targets), so update the metadata if the item exists and
-       add it outright when it does not. -->
+       Microsoft.NET.ILLink.targets), so replace any existing item and create it when
+       absent to ensure RootMode="all". -->
   <Target Name="RootEntireIntermediateAssembly" AfterTargets="PrepareForILLink" Condition="'$(OutputType)' != 'Exe'">
     <ItemGroup>
       <TrimmerRootAssembly Remove="@(IntermediateAssembly->'%(Filename)')" />