core

.NET 8.0 Known Issues

You may encounter the following known issues, which may include workarounds, mitigations, or expected resolution timeframes.

.NET SDK

[8.0.100-preview.1.23115.2] analyzer CA2009 throws InvalidCastException at runtime could cause a build failure

CA2009: Do not call ToImmutableCollection on an ImmutableCollection value analyzer regressed in .NET 8 preview 1, the regression could cause a build failure if:

CA2009 severity is set at warning level: dotnet_diagnostic.CA2009.severity = warning (by default it is suggestion)
And the AD0001 is at warning level (by default it is warning)
And the .NET 8 preview 1 SDK is being used for build
And the project warns as error <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
And the projects have a code section that calls ToImmutableArray() on an array instance, for example:

public ImmutableArray<int>  Method(int [] arr)
{
    return arr.ToImmutableArray();
}

Then the build would fail with an error:

error AD0001: Analyzer 'Microsoft.NetCore.Analyzers.ImmutableCollections.DoNotCallToImmutableCollectionOnAnImmutableCollectionValueAnalyzer' threw an exception of type 'System.InvalidCastException' with message 'Unable to cast object of type 'Microsoft.CodeAnalysis.CSharp.Symbols.PublicModel.ArrayTypeSymbol' to type 'Microsoft.CodeAnalysis.INamedTypeSymbol'.

Resolution

The regression is fixed in .NET 8 preview 2. Could upgrade into .NET 8 preview 2 or above
Lower the CA2009 analyzer severity to suggestion or none : dotnet_diagnostic.CA2009.severity = none
Lower the AD0001 diagnostic severity to suggestion or none : dotnet_diagnostic.CA2009.severity = suggestion

.NET MAUI

For details about known issues, please refer to the individual repositories:

Native AOT Support in .NET

For details about known issues, please reference to the pinned issue in this repo.

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