Misaligned read in 9.0.300 causes a razor generator crash

[333fred]

In Azure Pipelines using ubuntu-latest image and 9.0.300 SDK all our builds failed due to

CSC error CS8785: Generator 'RazorSourceGenerator' failed to generate source. It will not contribute to the output and compilation errors may occur as a result. Exception was of type 'ArgumentOutOfRangeException' with message 'Specified argument was out of the range of valid values.'. [/home/vsts/work/1/s/src/***.Web/***.Web.csproj]

Messages
    Microsoft (R) Visual C# Compiler version 4.14.0-3.25218.8 (d7bde97e)
    Copyright (C) Microsoft Corporation. All rights reserved.
    System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
    at Microsoft.AspNetCore.Razor.Language.CodeGeneration.CodeWriter.Reader.Read(Char[] buffer, Int32 index, Int32 count)
    at System.IO.TextReader.ReadBlock(Char[] buffer, Int32 index, Int32 count)
    at Microsoft.CodeAnalysis.Text.LargeText.ReadChunksFromTextReader(TextReader reader, Int32 maxCharRemainingGuess, Boolean throwIfBinaryDetected)
    at Microsoft.AspNetCore.Razor.Language.CodeGeneration.CodeWriter.GetText()
    at Microsoft.AspNetCore.Razor.Language.CodeGeneration.DefaultDocumentWriter.WriteDocument(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
    at Microsoft.AspNetCore.Razor.Language.DefaultRazorCSharpLoweringPhase.ExecuteCore(RazorCodeDocument codeDocument, CancellationToken cancellationToken)
    at Microsoft.AspNetCore.Razor.Language.RazorEnginePhaseBase.Execute(RazorCodeDocument codeDocument, CancellationToken cancellationToken)
    at Microsoft.NET.Sdk.Razor.SourceGenerators.SourceGeneratorProjectEngine.ExecutePhases(ReadOnlySpan`1 phases, RazorCodeDocument codeDocument)
    at Microsoft.NET.Sdk.Razor.SourceGenerators.SourceGeneratorProjectEngine.ProcessRemaining(SourceGeneratorRazorCodeDocument sgDocument)
    at Microsoft.NET.Sdk.Razor.SourceGenerators.RazorSourceGenerator.<>c__DisplayClass6_2.<Initialize>b__26(ValueTuple`3 pair, CancellationToken _)
    at Microsoft.CodeAnalysis.TransformNode`2.<>c__DisplayClass6_0.<.ctor>b__0(TInput i, CancellationToken token)
    at Microsoft.CodeAnalysis.TransformNode`2.UpdateStateTable(Builder builder, NodeStateTable`1 previousTable, CancellationToken cancellationToken)
    -----

Setting fixed SDK version to 9.0.204 in Azure Pipeline fix issue with builds.

I can provide binlog on request (privately)

Originally posted by @alfeg in #9885

[333fred]

@alfeg, @srudenkoyb, @jscarle:

Thanks for the logs. We've traced it to a very precise loop error that will be fixed in #11861. We expect to publish a toolset package you can use to work around the error in the next couple of days, with permanent fix in the next version. Thanks for the prompt reporting!

Originally posted by @333fred in #9885

[333fred]

To work around the razor issue before new SDK version is released, you can temporarily reference razor toolset package:

https://dev.azure.com/dnceng/public/_artifacts/feed/dotnet-tools/NuGet/Microsoft.Net.Compilers.Razor.Toolset/overview/9.0.0-preview.25264.2

You need to add the nuget feed, e.g., like this to a nuget.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <clear />
    <add key="nuget" value="https://api.nuget.org/v3/index.json" />
    <add key="dotnet-tools" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json" />
  </packageSources>
</configuration>

And then you can install the toolset package with the fix in your project file or Directory.Build.props:

  <ItemGroup>
    <PackageReference Include="Microsoft.Net.Compilers.Razor.Toolset" Version="9.0.0-preview.25264.2">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
  </ItemGroup>

Originally posted by @jjonescz in #9885

[333fred]

A simpler workaround is now available: Simply depend on https://www.nuget.org/packages/Microsoft.Net.Compilers.Razor.Toolset/9.0.0-preview.25264.2, no need for the additional nuget.config entry.

  <ItemGroup>
    <PackageReference Include="Microsoft.Net.Compilers.Razor.Toolset" Version="9.0.0-preview.25264.2">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
  </ItemGroup>

Warning

Do not depend on this package long-term. Please remove it as soon as there an SDK with this fix in it, which we expect to be 9.0.301.

[jscarle]

@333fred I can confirm that building our solution using .NET 9.0.300 and this package does indeed resolve the issue.

[333fred]

Thanks for the confirmation!