Unnecessary suppression errors showing up in build using .NET 8 Preview 7 SDK

[mthalman]

When attempting to build the runtime repo with the latest build of .NET 8 Preview 7 SDK, it produces the following errors:

CoreCLR

/vmr/src/runtime/artifacts/source-build/self/package-cache/microsoft.dotnet.apicompat.task/8.0.100-preview.7.23364.43/build/Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : Unnecessary suppressions found. The APICompat suppression file can be updated by rebuilding with '/p:ApiCompatGenerateSuppressionFile=true' [/vmr/src/runtime/artifacts/source-build/self/src/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj]
/vmr/src/runtime/artifacts/source-build/self/package-cache/microsoft.dotnet.apicompat.task/8.0.100-preview.7.23364.43/build/Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : CP0001 (Target: 'T:System.Diagnostics.DebuggerGuidedStepThroughAttribute') [/vmr/src/runtime/artifacts/source-build/self/src/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj]
/vmr/src/runtime/artifacts/source-build/self/package-cache/microsoft.dotnet.apicompat.task/8.0.100-preview.7.23364.43/build/Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : CP0001 (Target: 'T:System.Runtime.CompilerServices.EagerStaticClassConstructionAttribute') [/vmr/src/runtime/artifacts/source-build/self/src/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj]
/vmr/src/runtime/artifacts/source-build/self/package-cache/microsoft.dotnet.apicompat.task/8.0.100-preview.7.23364.43/build/Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : CP0016 (Target: 'M:System.Runtime.InteropServices.Marshal.GetObjectForNativeVariant``1(System.IntPtr)->T?:[T:System.Diagnostics.CodeAnalysis.MaybeNullAttribute]') [/vmr/src/runtime/artifacts/source-build/self/src/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj]

Libraries

/vmr/src/runtime/artifacts/source-build/self/package-cache/microsoft.dotnet.apicompat.task/8.0.100-preview.7.23364.43/build/Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : Unnecessary suppressions found. The APICompat suppression file can be updated by rebuilding with '/p:ApiCompatGenerateSuppressionFile=true' [/vmr/src/runtime/artifacts/source-build/self/src/src/libraries/System.Runtime.InteropServices.JavaScript/src/System.Runtime.InteropServices.JavaScript.csproj]
/vmr/src/runtime/artifacts/source-build/self/package-cache/microsoft.dotnet.apicompat.task/8.0.100-preview.7.23364.43/build/Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : CP0001 (Target: 'T:System.Runtime.InteropServices.JavaScript.WebWorker', Left: 'ref/net8.0/System.Runtime.InteropServices.JavaScript.dll', Right: 'runtimes/browser/lib/net8.0/System.Runtime.InteropServices.JavaScript.dll') [/vmr/src/runtime/artifacts/source-build/self/src/src/libraries/System.Runtime.InteropServices.JavaScript/src/System.Runtime.InteropServices.JavaScript.csproj]

These suppressions only seem to be relevant to Windows. So there needs to be a way to exclude these suppressions for Linux but include them for Windows.

[ericstj]

We shouldn't have cases where we only have unnecessary suppressions on some platforms - that would indicate some inconsistencies in public API per platform.

[mthalman]

We shouldn't have cases where we only have unnecessary suppressions on some platforms - that would indicate some inconsistencies in public API per platform.

I attempted to remove the suppressions in #89186 but it led to all these failures in the Windows build jobs. These errors didn't show up in the Linux jobs.

##[error].packages\microsoft.dotnet.apicompat.task\8.0.100-preview.7.23329.3\build\Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : (NETCORE_ENGINEERING_TELEMETRY=Build) API compatibility errors between 'ref/net8.0/System.Private.CoreLib.dll' (left) and 'lib/net8.0/System.Private.CoreLib.dll' (right):
D:\a\_work\1\s\.packages\microsoft.dotnet.apicompat.task\8.0.100-preview.7.23329.3\build\Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error CP0016: Cannot add attribute 'System.Diagnostics.CodeAnalysis.MaybeNullAttribute' to 'System.Runtime.InteropServices.Marshal.GetObjectForNativeVariant<T>(nint)'. [D:\a\_work\1\s\src\coreclr\nativeaot\System.Private.CoreLib\src\System.Private.CoreLib.csproj]
##[error].packages\microsoft.dotnet.apicompat.task\8.0.100-preview.7.23329.3\build\Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error CP0016: (NETCORE_ENGINEERING_TELEMETRY=Build) Cannot add attribute 'System.Diagnostics.CodeAnalysis.MaybeNullAttribute' to 'System.Runtime.InteropServices.Marshal.GetObjectForNativeVariant<T>(nint)'.
D:\a\_work\1\s\.packages\microsoft.dotnet.apicompat.task\8.0.100-preview.7.23329.3\build\Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : API breaking changes found. If those are intentional, the APICompat suppression file can be updated by rebuilding with '/p:ApiCompatGenerateSuppressionFile=true' [D:\a\_work\1\s\src\coreclr\nativeaot\System.Private.CoreLib\src\System.Private.CoreLib.csproj]
##[error].packages\microsoft.dotnet.apicompat.task\8.0.100-preview.7.23329.3\build\Microsoft.DotNet.ApiCompat.ValidateAssemblies.Common.targets(16,5): error : (NETCORE_ENGINEERING_TELEMETRY=Build) API breaking changes found. If those are intentional, the APICompat suppression file can be updated by rebuilding with '/p:ApiCompatGenerateSuppressionFile=true'

[ericstj]

#87567 introduced the public API inconsistencies in System.Runtime.InteropServices.JavaScript cc @pavelsavara

GetObjectForNativeVariant -> Missing nullable annotation here:

runtime/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshal.Com.cs

Line 348 in 7469976

public static T GetObjectForNativeVariant<T>(IntPtr pSrcNativeVariant)

Return type should be T? to match others. Then we should remove suppression.

DebuggerGuidedStepThroughAttribute and EagerStaticClassConstructionAttribute - haven't seen this yet but will update once I see root cause.

[MichalPetryka]

EagerStaticClassConstructionAttribute is a NativeAOT only undocumented attribute, it's not a part of the public API.
cc @MichalStrehovsky