From c5c1e2d802fb7f40d7b49037bba767a6829817d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexander=20K=C3=B6plinger?= <alex.koeplinger@outlook.com>
Date: Tue, 18 Jan 2022 18:10:45 +0100
Subject: [PATCH] Fix DotnetSharedFrameworkTaskDir to not rely on
 DotnetBuildFromSource (#8355)

After https://github.com/dotnet/arcade/pull/8338 we saw a build error in a dotnet/runtime build job that tries to validate source-build but still uses the non-source-built arcade packages:

```
 /__w/1/s/artifacts/source-build/self/src/src/libraries/ref.proj(68,5): error MSB4062: The "CreateFrameworkListFile" task could not be loaded from the assembly /__w/1/s/artifacts/source-build/self/package-cache/microsoft.dotnet.sharedframework.sdk/7.0.0-beta.22064.25/sdk/../tools/net6.0/Microsoft.DotNet.SharedFramework.Sdk.dll. Could not load file or assembly '/__w/1/s/artifacts/source-build/self/package-cache/microsoft.dotnet.sharedframework.sdk/7.0.0-beta.22064.25/tools/net6.0/Microsoft.DotNet.SharedFramework.Sdk.dll'. The system cannot find the file specified.
```

This is because the non-source-built arcade packages use netcoreapp3.1 libraries instead of  net6.0, but we're still setting DotnetBuildFromSource=true in those builds.

Instead of using DotnetBuildFromSource to switch between libraries we can check for the existence of the net6.0 folder which works in both scenarios.
---
 src/Microsoft.DotNet.SharedFramework.Sdk/sdk/Sdk.props | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/Microsoft.DotNet.SharedFramework.Sdk/sdk/Sdk.props b/src/Microsoft.DotNet.SharedFramework.Sdk/sdk/Sdk.props
index 4d35a9838a8..deee11c08b3 100644
--- a/src/Microsoft.DotNet.SharedFramework.Sdk/sdk/Sdk.props
+++ b/src/Microsoft.DotNet.SharedFramework.Sdk/sdk/Sdk.props
@@ -8,11 +8,10 @@
   -->
 
   <PropertyGroup Condition="'$(DotNetSharedFrameworkTaskDir)' == ''">
-    <DotNetSharedFrameworkTaskDir Condition="'$(MSBuildRuntimeType)' == 'core'">$(MSBuildThisFileDirectory)../tools/netcoreapp3.1/</DotNetSharedFrameworkTaskDir>
-    <DotNetSharedFrameworkTaskDir Condition="'$(MSBuildRuntimeType)' != 'core'">$(MSBuildThisFileDirectory)../tools/net472/</DotNetSharedFrameworkTaskDir>
-
     <!-- Workaround for https://github.com/dotnet/arcade/issues/7413 -->
-    <DotNetSharedFrameworkTaskDir Condition="'$(MSBuildRuntimeType)' == 'core' and '$(DotNetBuildFromSource)' == 'true'">$(MSBuildThisFileDirectory)../tools/net6.0/</DotNetSharedFrameworkTaskDir>
+    <DotNetSharedFrameworkTaskDir Condition="'$(MSBuildRuntimeType)' == 'core' and Exists('$(MSBuildThisFileDirectory)../tools/net6.0/')">$(MSBuildThisFileDirectory)../tools/net6.0/</DotNetSharedFrameworkTaskDir>
+    <DotNetSharedFrameworkTaskDir Condition="'$(MSBuildRuntimeType)' == 'core' and '$(DotNetSharedFrameworkTaskDir)' == ''">$(MSBuildThisFileDirectory)../tools/netcoreapp3.1/</DotNetSharedFrameworkTaskDir>
+    <DotNetSharedFrameworkTaskDir Condition="'$(MSBuildRuntimeType)' != 'core'">$(MSBuildThisFileDirectory)../tools/net472/</DotNetSharedFrameworkTaskDir>
   </PropertyGroup>
 
   <PropertyGroup>