CommunityToolkit.Mvvm source generators fail on Visual Studio 17.4.0 Preview 6 and 17.5.0 Preview 1

[nxtn-staged]

Note: this is an external issue in Roslyn, see: dotnet/roslyn#67123.

Describe the bug

I recently updated Visual Studio to 17.5.0 Preview 1.0 and my project starts to fail to build.

1>CSC : warning CS8785: Generator 'INotifyPropertyChangedGenerator' failed to generate source. It will not contribute to the output and compilation errors may occur as a result. Exception was of type 'MissingMethodException' with message 'Method not found: 'System.ReadOnlySpan`1<System.__Canon> System.Collections.Immutable.ImmutableArray`1.AsSpan()'.'
1>CSC : warning CS8785: Generator 'ObservablePropertyGenerator' failed to generate source. It will not contribute to the output and compilation errors may occur as a result. Exception was of type 'MissingMethodException' with message 'Method not found: 'System.ReadOnlySpan`1<System.__Canon> System.Collections.Immutable.ImmutableArray`1.AsSpan()'.'

Regression

No response

Steps to reproduce

1. Add project files

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.1.0-preview1" />
  </ItemGroup>
  
</Project>

using CommunityToolkit.Mvvm.ComponentModel;

[INotifyPropertyChanged]
partial class Foo
{
    [ObservableProperty]
    private int bar;
}

static class Program
{
    static void Main()
    {
        new Foo().Bar = 42;
    }
}

2. Build in Visual Studio

Expected behavior

It works.

Screenshots

No response

IDE and version

VS 2022 Preview

IDE version

No response

Nuget packages

• CommunityToolkit.Common
• CommunityToolkit.Diagnostics
• CommunityToolkit.HighPerformance
• CommunityToolkit.Mvvm (aka MVVM Toolkit)

Nuget package version(s)

8.1.0-preview1

Additional context

I can't always reproduce this. I'm also not sure if it's a problem in this project, but my other source generator dependencies are not affected.

Help us help you

Yes, but only if others can assist

[Sergio0694]

Mmh this is weird. Just to clarify:

• Does this also repro on VS 17.4?
• Does this repro on 8.0.0 as well, or just on 8.1.0-Preview1?

[nxtn-staged]

It first reproduced when I updated Visual Studio to the 17.4.0 Preview 6 and some package dependencies. Downgrading CommunityToolkit.Mvvm from 8.1.0-Preview1 to 8.0.0 didn't help, and I managed to work around it by downgrading Microsoft.Windows.CsWin32 from 0.2.104-beta to 0.2.63-beta 😕. After updating VS to 17.5.0 Preview 1 it doesn't work anymore.

[arkadym]

Im stuck with below errors after upgrade

1>...\CommunityToolkit.Maui.Markup.SourceGenerators\CommunityToolkit.Maui.Markup.SourceGenerators.TextAlignmentExtensionsGenerator\EditorTextAlignmentExtensions.g.cs(122,147,122,167): error CS0121: The call is ambiguous between the following methods or properties: 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Editor.TextCenterHorizontal(Microsoft.Maui.Controls.Editor)' and 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Editor.TextCenterHorizontal(Microsoft.Maui.Controls.Editor)'
1>...\CommunityToolkit.Maui.Markup.SourceGenerators\CommunityToolkit.Maui.Markup.SourceGenerators.TextAlignmentExtensionsGenerator\EntryTextAlignmentExtensions.g.cs(122,145,122,165): error CS0121: The call is ambiguous between the following methods or properties: 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Entry.TextCenterHorizontal(Microsoft.Maui.Controls.Entry)' and 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Entry.TextCenterHorizontal(Microsoft.Maui.Controls.Entry)'
1>...\CommunityToolkit.Maui.Markup.SourceGenerators\CommunityToolkit.Maui.Markup.SourceGenerators.TextAlignmentExtensionsGenerator\LabelTextAlignmentExtensions.g.cs(122,145,122,165): error CS0121: The call is ambiguous between the following methods or properties: 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Label.TextCenterHorizontal(Microsoft.Maui.Controls.Label)' and 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Label.TextCenterHorizontal(Microsoft.Maui.Controls.Label)'
1>...\CommunityToolkit.Maui.Markup.SourceGenerators\CommunityToolkit.Maui.Markup.SourceGenerators.TextAlignmentExtensionsGenerator\PickerTextAlignmentExtensions.g.cs(122,147,122,167): error CS0121: The call is ambiguous between the following methods or properties: 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Picker.TextCenterHorizontal(Microsoft.Maui.Controls.Picker)' and 'CommunityToolkit.Maui.Markup.TextAlignmentExtensions_Picker.TextCenterHorizontal(Microsoft.Maui.Controls.Picker)'

[huoyaoyuan]

It reproduces for VS 17.4 stable, for version 8.0.0 and 8.1.0-preview1 both.

[huoyaoyuan]

In decompilation, the System.Collections.Immutable.dll in .NET Framework version of VS at MSBuild\Current\bin\Roslyn does have the method AsSpan(). So does the one at MSBuild\Current\bin.
I have totally no idea why it can cause MissingMethodException.

A workaround is to run dotnet build once in command line to use the .NET Core version of compiler, as long as it's not a WinUI project (or the vm project has been separated from UI).

[Sergio0694]

Mmh this is weird. I can't repro locally with VS 17.4, but the fact people can with 8.0 stable is worrying.

@sharwell @chsienki do you have any idea what could be causing this? 😅

[JPhilC]

Yesterday I was trying to work out why the source generators sometimes worked with WPF (,NET Framework 4.7.1) App and sometimes didn't. This morning I update VS 2022 to 17.4.1 and the source generators have stopped working completely.

Testing with the following code in a class definition.

using CommunityToolkit.Mvvm.ComponentModel;

namespace WpfApp4
{
    public class MainWindowModelview: ObservableObject
    {
        [ObservableProperty]
        private string _firstName = "Phil";

        
    }
}

The solution builds but then the expected property FirstName is not generated by the source generator. If I look under References\Analyzers the Analyzers node is not expandable.

Steps to reproduce,

Create a new WPF Desktop App (.NET Framework 4.7.1)
Add nuget V8.1.0 ..Preview 1
Add class MainMenuModelview with above definition.

Build.

Additional info...

If I convert packages.conf to ReferencedPackages and include transitive assemblies by ticking the top level box then the source generation starts but it leads to a whole load of messages at the top of the Visual Studio IDE.

and the following build errors.

The stack trace of the first messages is:

System.ArgumentException : An element with the same key but a different value already exists. Key: '(DocumentId, #a64613e5-d79c-9c32-3ac4-a27dcc380fd0 - System.Diagnostics.CodeAnalysis.NotNullAttribute.g.cs)'
   at System.Collections.Immutable.ImmutableSortedDictionary`2.FillFromEmpty(IEnumerable`1 items,Boolean overwriteOnCollision)
   at System.Collections.Immutable.ImmutableSortedDictionary`2.AddRange(IEnumerable`1 items,Boolean overwriteOnCollision,Boolean avoidToSortedMap)
   at System.Collections.Immutable.ImmutableSortedDictionary.ToImmutableSortedDictionary[TSource,TKey,TValue](IEnumerable`1 source,Func`2 keySelector,Func`2 elementSelector,IComparer`1 keyComparer)
   at Microsoft.CodeAnalysis.TextDocumentStates`1..ctor(IEnumerable`1 states)
   at async Microsoft.CodeAnalysis.SolutionState.CompilationTracker.FinalizeCompilationAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.SolutionState.CompilationTracker.BuildCompilationInfoAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.SolutionState.CompilationTracker.GetOrBuildCompilationInfoAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.SolutionState.CompilationTracker.GetCompilationSlowAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.Document.GetSemanticModelAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.SemanticDocument.CreateAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.IntroduceVariable.AbstractIntroduceVariableService`6.IntroduceVariableAsync[TService,TExpressionSyntax,TTypeSyntax,TTypeDeclarationSyntax,TQueryExpressionSyntax,TNameSyntax](<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.IntroduceVariable.IntroduceVariableCodeRefactoringProvider.ComputeRefactoringsAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.CodeRefactorings.CodeRefactoringService.GetRefactoringFromProviderAsync(<Unknown Parameters>)

In all there are 12 messages they all seem to have the same stack trace.

'IntroduceVariableCodeRefactoringProvider' encountered an error and has been disabled.
'CSharpConvertConcatenationToInterpolatedStringRefactoringProvider' encountered an error and has been disabled.
'CSharpConvertPlaceholderToInterpolatedStringRefactoringProvider' encountered an error and has been disabled.
'CSharpConvertIfToSwitchCodeRefactoringProvider' encountered an error and has been disabled.
'CSharpPullMemberUpCodeRefactoringProvider' encountered an error and has been disabled.
'CSharpMoveStaticMembersRefactoringProvider' encountered an error and has been disabled.
'CSharpExtractClassCodeRefactoringProvider' encountered an error and has been disabled.
'CSharpAddDebuggerDisplayCodeRefactoringProvider' encountered an error and has been disabled.
'MoveTypeCodeRefactoringProvider' encountered an error and has been disabled.
'MoveToNamespaceCodeActionProvider' encountered an error and has been disabled.
'GenerateDefaultConstructorsCodeRefactoringProvider' encountered an error and has been disabled.
'EncapsulateFieldRefactoringProvider' encountered an error and has been disabled.

[jansaris]

On our build environment at the customer we also have this issue.
It's a build-flipper, since it sometime causes the build to fail and sometimes to succeed

We can't see any difference in the generated csproj file when looking at the msbuild binlog file :-(

[Sergio0694]

Given that there's a whole bunch of inbox analyzers also failing for the same reason, this seems unrelated from the MVVM Toolkit specifically. Also note that the generators have known issue with non-SDK-style .NET Framework projects. Does the issue still repro for you if you switch to an SDK-style .csproj format?

[Lightczx]

I'm using .NET 7, VS2022 17.4.2, SDK style project

Still can reproduce these,@Sergio0694
Everything works fine before I upgrade my Microsoft.Windows.CsWin32

<PackageReference Include="Microsoft.Windows.CsWin32" Version="0.2.138-beta">
<PackageReference Include="Microsoft.Windows.CsWin32" Version="0.2.164-beta">