From da9a574e9c030f1ec2fe1b31829c5deaa53f3a7e Mon Sep 17 00:00:00 2001
From: Larry Ewing <lewing@microsoft.com>
Date: Mon, 27 Jul 2026 09:26:33 -0500
Subject: [PATCH 1/2] [wasm] Give the CoreCLR wasm SDK its own props

The workload pack's Sdk.targets imported BrowserWasmApp.props (and through it
WasmApp.Common.props) unconditionally, so the CoreCLR flavor picked up Mono's
WasmNestedPublishAppDependsOn=_WasmBuildAppCore even though WasmApp.Common.targets,
which defines that target, is never imported on the CoreCLR path. Publishing a
CoreCLR browser-wasm app therefore failed with:

  MSB4057: The target "_WasmBuildAppCore" does not exist in the project.

Add BrowserWasmApp.CoreCLR.props with just the flavor-neutral properties
(TargetOS/TargetArchitecture/RuntimeIdentifier) and import the props/targets pair
per flavor, mirroring what the in-tree WasmApp.InTree.props/targets already do.
The Mono files are untouched.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b49e36e8-8a37-48ef-b7e8-54ac6443ea19
---
 .../browser/build/BrowserWasmApp.CoreCLR.props  | 17 +++++++++++++++++
 ...icrosoft.NET.Runtime.WebAssembly.Sdk.pkgproj |  1 +
 .../Sdk/Sdk.targets.in                          |  3 ++-
 3 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 src/mono/browser/build/BrowserWasmApp.CoreCLR.props

diff --git a/src/mono/browser/build/BrowserWasmApp.CoreCLR.props b/src/mono/browser/build/BrowserWasmApp.CoreCLR.props
new file mode 100644
index 00000000000000..8a0a77b249068a
--- /dev/null
+++ b/src/mono/browser/build/BrowserWasmApp.CoreCLR.props
@@ -0,0 +1,17 @@
+<Project>
+  <!--
+    CoreCLR counterpart of BrowserWasmApp.props. The two are mutually exclusive: the workload
+    pack (Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in) imports this one alongside
+    BrowserWasmApp.CoreCLR.targets, and the Mono one alongside BrowserWasmApp.targets.
+
+    Only the flavor-neutral properties are repeated here. In particular the Mono app-build
+    target lists from WasmApp.Common.props (WasmBuildAppDependsOn, WasmNestedPublishAppDependsOn)
+    are deliberately not set: they name targets defined in WasmApp.Common.targets, which the
+    CoreCLR path does not import, and BrowserWasmApp.CoreCLR.targets defines its own equivalents.
+  -->
+  <PropertyGroup>
+    <TargetOS>browser</TargetOS>
+    <TargetArchitecture>wasm</TargetArchitecture>
+    <RuntimeIdentifier>browser-wasm</RuntimeIdentifier>
+  </PropertyGroup>
+</Project>
diff --git a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj
index e27ba5d289a1e5..d0694fb4fef4fd 100644
--- a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj
+++ b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj
@@ -17,6 +17,7 @@
 
     <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.props" TargetPath="Sdk" />
     <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.targets" TargetPath="Sdk" />
+    <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.CoreCLR.props" TargetPath="Sdk" />
     <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.CoreCLR.targets" TargetPath="Sdk" />
 
     <PackageFile Include="$(WasmProjectRoot)build\WasmApp.Common.props" TargetPath="Sdk" />
diff --git a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in
index 9d3818cdbe0b5f..f80f682f914678 100644
--- a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in
+++ b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in
@@ -12,7 +12,8 @@
     <WasmEmitSymbolMap Condition="'$(UsingMicrosoftNETSdkBlazorWebAssembly)' != 'true' and '$(UsingMicrosoftNETSdkWebAssembly)' != 'true' and '$(WasmEmitSymbolMap)' == '' and '$(RunAOTCompilation)' != 'true'">true</WasmEmitSymbolMap>
   </PropertyGroup>
 
-  <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.props" />
+  <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.props" Condition="'$(UseMonoRuntime)' != 'false'" />
   <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.targets" Condition="'$(UseMonoRuntime)' != 'false'" />
+  <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.CoreCLR.props" Condition="'$(UseMonoRuntime)' == 'false'" />
   <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.CoreCLR.targets" Condition="'$(UseMonoRuntime)' == 'false'" />
 </Project>

From 84a7701eec3eba0f43e89eabe9483e7047960489 Mon Sep 17 00:00:00 2001
From: Larry Ewing <lewing@microsoft.com>
Date: Mon, 27 Jul 2026 13:13:49 -0500
Subject: [PATCH 2/2] Drop the CoreCLR props file, conditioning the import is
 enough

Per review feedback, none of the three properties are needed:

- RuntimeIdentifier is set by the WebAssembly SDK (WasmSdk/Sdk/Sdk.props and
  Microsoft.NET.Sdk.WebAssembly.Pack.props), both before this Sdk.targets runs.
- TargetOS/TargetArchitecture are only consumed in-tree (eng/native.wasm.targets);
  eng/OSArch.props already derives both from RuntimeIdentifier == 'browser-wasm',
  which is why in-tree CoreCLR works today without importing BrowserWasmApp.props.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b49e36e8-8a37-48ef-b7e8-54ac6443ea19
---
 .../browser/build/BrowserWasmApp.CoreCLR.props  | 17 -----------------
 ...icrosoft.NET.Runtime.WebAssembly.Sdk.pkgproj |  1 -
 .../Sdk/Sdk.targets.in                          |  7 ++++++-
 3 files changed, 6 insertions(+), 19 deletions(-)
 delete mode 100644 src/mono/browser/build/BrowserWasmApp.CoreCLR.props

diff --git a/src/mono/browser/build/BrowserWasmApp.CoreCLR.props b/src/mono/browser/build/BrowserWasmApp.CoreCLR.props
deleted file mode 100644
index 8a0a77b249068a..00000000000000
--- a/src/mono/browser/build/BrowserWasmApp.CoreCLR.props
+++ /dev/null
@@ -1,17 +0,0 @@
-<Project>
-  <!--
-    CoreCLR counterpart of BrowserWasmApp.props. The two are mutually exclusive: the workload
-    pack (Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in) imports this one alongside
-    BrowserWasmApp.CoreCLR.targets, and the Mono one alongside BrowserWasmApp.targets.
-
-    Only the flavor-neutral properties are repeated here. In particular the Mono app-build
-    target lists from WasmApp.Common.props (WasmBuildAppDependsOn, WasmNestedPublishAppDependsOn)
-    are deliberately not set: they name targets defined in WasmApp.Common.targets, which the
-    CoreCLR path does not import, and BrowserWasmApp.CoreCLR.targets defines its own equivalents.
-  -->
-  <PropertyGroup>
-    <TargetOS>browser</TargetOS>
-    <TargetArchitecture>wasm</TargetArchitecture>
-    <RuntimeIdentifier>browser-wasm</RuntimeIdentifier>
-  </PropertyGroup>
-</Project>
diff --git a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj
index d0694fb4fef4fd..e27ba5d289a1e5 100644
--- a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj
+++ b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Microsoft.NET.Runtime.WebAssembly.Sdk.pkgproj
@@ -17,7 +17,6 @@
 
     <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.props" TargetPath="Sdk" />
     <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.targets" TargetPath="Sdk" />
-    <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.CoreCLR.props" TargetPath="Sdk" />
     <PackageFile Include="$(BrowserProjectRoot)build\BrowserWasmApp.CoreCLR.targets" TargetPath="Sdk" />
 
     <PackageFile Include="$(WasmProjectRoot)build\WasmApp.Common.props" TargetPath="Sdk" />
diff --git a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in
index f80f682f914678..54b39b2384c41c 100644
--- a/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in
+++ b/src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets.in
@@ -12,8 +12,13 @@
     <WasmEmitSymbolMap Condition="'$(UsingMicrosoftNETSdkBlazorWebAssembly)' != 'true' and '$(UsingMicrosoftNETSdkWebAssembly)' != 'true' and '$(WasmEmitSymbolMap)' == '' and '$(RunAOTCompilation)' != 'true'">true</WasmEmitSymbolMap>
   </PropertyGroup>
 
+  <!-- Mono and CoreCLR each get their own set of targets. BrowserWasmApp.props (and the
+       WasmApp.Common.props it imports) is Mono-only: it seeds target lists such as
+       WasmNestedPublishAppDependsOn with targets defined in WasmApp.Common.targets, which the
+       CoreCLR path does not import. CoreCLR needs no props counterpart: RuntimeIdentifier comes
+       from the WebAssembly SDK, and TargetOS/TargetArchitecture are only consumed in-tree, where
+       eng/OSArch.props derives them from the RID. -->
   <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.props" Condition="'$(UseMonoRuntime)' != 'false'" />
   <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.targets" Condition="'$(UseMonoRuntime)' != 'false'" />
-  <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.CoreCLR.props" Condition="'$(UseMonoRuntime)' == 'false'" />
   <Import Project="$(MSBuildThisFileDirectory)\BrowserWasmApp.CoreCLR.targets" Condition="'$(UseMonoRuntime)' == 'false'" />
 </Project>