Merge pull request #2882 from InKahootz/msbuild-wpf-warning

Clarify WPF specific flags and subsequent warning

Author: asbjornu

docs/input/docs/usage/msbuild.md

@@ -51,16 +51,39 @@ The next thing you need to do is to remove the `Assembly*Version` attributes fro
 your `Properties\AssemblyInfo.cs` files. This puts GitVersion.MsBuild in charge of
 versioning your assemblies.
 
-DotNet SDK-style projects will generate Assembly Version info along with other
-Assembly Info in a 'projectname.AssemblyInfo.cs' file, conflicting with GitVersion.
-So, you will need to edit your project. Add [GenerateAssemblyFileVersionAttribute](https://docs.microsoft.com/en-us/dotnet/core/project-sdk/msbuild-props#generateassemblyfileversionattribute)
-under the first PropertyGroup and set it to `false`:
+### WPF specific concerns
+
+One futhur step needs to be taken for SDK-style WPF projects.
+
+Building projects with .NET Core SDK with a version lower than v5.0.200
+requires turning off automatic generation of the different versioning attributes.
+GitVersion usually controls these properties but cannot during WPF specific
+targets that generate a temporary project.
 
 ```xml
-<!-- GitVersion DotNet SDK Compatibility -->
-<GenerateAssemblyFileVersionAttribute>false</GenerateAssemblyFileVersionAttribute>
+<PropertyGroup>
+  <!-- Wpf workaround: GitVersion and .NET SDK < v5.0.200 -->
+  <GenerateAssemblyFileVersionAttribute>false</GenerateAssemblyFileVersionAttribute>
+  <GenerateAssemblyInformationalVersionAttribute>false</GenerateAssemblyInformationalVersionAttribute>
+  <GenerateAssemblyVersionAttribute>false</GenerateAssemblyVersionAttribute>
+</PropertyGroup>
 ```
 
+For .NET Core SDK v5.0.200 to v6.0.0-preview.1, a opt-in flag was introduced to
+allow package references to be imported to the temporary project.
+You can now remove the previous versioning attributes and replace them with
+a single property.
+
+```xml
+<PropertyGroup>
+  <!-- WPF workaround: GitVersion and .NET SDK between v5.0.200 and v6.0.0-preview.2  -->
+  <IncludePackageReferencesDuringMarkupCompilation>true</IncludePackageReferencesDuringMarkupCompilation>
+</PropertyGroup>
+```
+
+You can remove all workarounds if you are building with .NET Core SDK
+v6.0.0-preview.2 or later as the flag is now opt-out.
+
 ### Done!
 
 The setup process is now complete and GitVersion.MsBuild should be working its magic,

src/GitVersion.MsBuild/msbuild/tools/GitVersion.MsBuild.props

@@ -54,6 +54,12 @@
         -->
         <GenerateGitVersionInformation Condition=" '$(GenerateGitVersionInformation)' == '' And '$(_TargetAssemblyProjectName)' != '' ">false</GenerateGitVersionInformation>
         <GenerateGitVersionInformation Condition=" '$(GenerateGitVersionInformation)' == '' ">true</GenerateGitVersionInformation>
+        <!--
+          Compounding on the previous "GenerateTemporaryTargetAssembly" explanation, "UpdateAssemblyInfo" is
+          also called in this temp-build. This results in a warning since we already updated assembly info.
+          Prevent UpdateAssemblyInfo from running a second time.
+        -->
+        <UpdateAssemblyInfo Condition=" '$(UpdateAssemblyInfo)' == 'true' And '$(_TargetAssemblyProjectName)' != '' ">false</UpdateAssemblyInfo>
 
         <!-- Property that enables GetVersion -->
         <GetVersion Condition=" '$(DisableGitVersionTask)' == 'true' ">false</GetVersion>