[.NET 8] Known Native AOT Issues

[captainsafia]

This issue outlines the set of features that are not yet supported fully in applications that have been AoT compiled to native code.

If you encounter problems in a preview that are not in the list below, please file an issue in the appropriate repo.

• ASP.NET Core
• .NET

8.0-preview4

Request Delegate Generator

• The Produces and Accepts metadata are not automatically added to endpoint metadata for a given endpoint. See Support metadata generation in RequestDelegate generator aspnetcore#46277.
• The generated code does not support parameters marked with AsParameters. See Support binding from types defined with an AsParameters attribute aspnetcore#46336.
• The generated code does not support route handlers that return an anonymous type. See RDG does not support route handlers that return an anonymous type aspnetcore#47244.
• The generated code does not support generic types from outer scope. See RDG does not support generic types from outer scope aspnetcore#47338
• The generated code does not support private parameter and return types. See RDG does not support private parameter and return types aspnetcore#47339
• The generated code does not support having two endpoints with the route handlers that only differ in nullability annotations. See [RDG] Route handlers with the same parameters but differing nullability produce compiler warnings aspnetcore#46622.
• The IEndpointRouteBuilder.Map and IEndpointRouteBuilder.MapMethods overloads are not supported. See RDG does not support certain RouteHandlerBuilder extension methods aspnetcore#47196.
• The generated code does not respect configured JsonSerializerOptions when reading from the request body. See Pass JsonSerializerOptions to ReadFromJsonAsync calls in RDG aspnetcore#47145.

System.Text.Json

• Publishing for Native AOT requires that all JSON (de)serialization use the JSON Source Generator. Any existing issues with the JSON Source Generator is also an issue for Native AOT.
  • Anonymous Types cannot be source generated
  • Compiler generated types, for example for IAsyncEnumerable, do not work. JsonSerializer.Serialize overloads accepting JsonSerializerContext don't support unspeakable types. runtime#84260
  • Deserializing and serializing enums with strings are not AOT-safe Provide trim/AOT-safe mechanism to (de)serialize enums from strings with JSON source-gen runtime#79311

8.0-preview3

### Request Delegate Generator - The `Produces` and `Accepts` metadata are not automatically added to endpoint metadata for a given endpoint. See https://github.com/dotnet/aspnetcore/issues/46277. - The generated code will not log, or throw exceptions in development mode, when parameter binding fails. Instead, the request will return a `400` status code. See https://github.com/dotnet/aspnetcore/issues/46362. - The generated code does not support parameters marked with `AsParameters`. See https://github.com/dotnet/aspnetcore/issues/46336. - The generated code does not support parameters processed as form data via `IFormCollection`, `IFormFile`, or `FromForm`. See https://github.com/dotnet/aspnetcore/issues/47200. - The generated code does not support route handlers that return an anonymous type. See https://github.com/dotnet/aspnetcore/issues/47244. - The generated code does not support generic types from outer scope. See https://github.com/dotnet/aspnetcore/issues/47338 - The generated code does not support private parameter and return types. See https://github.com/dotnet/aspnetcore/issues/47339 - The generated code does not respect the `RouteHandlerOptions.ThrowOnBadRequest` property. See https://github.com/dotnet/aspnetcore/issues/46362. - The generated code does not support having two endpoints with the route handlers that only differ in nullability annotations. See https://github.com/dotnet/aspnetcore/issues/46622. - The `IEndpointRouteBuilder.Map` and `IEndpointRouteBuilder.MapMethods` overloads are not supported. See https://github.com/dotnet/aspnetcore/issues/47196. - The generated code does not respect configured `JsonSerializerOptions` when reading from the request body. See https://github.com/dotnet/aspnetcore/issues/47145. - Generation fails when default parameter values are provided. See https://github.com/dotnet/aspnetcore/issues/47266

System.Text.Json

• Publishing for Native AOT requires that all JSON (de)serialization use the JSON Source Generator. Any existing issues with the JSON Source Generator is also an issue for Native AOT.
  • Anonymous Types cannot be source generated
  • Compiler generated types, for example for IAsyncEnumerable, do not work. JsonSerializer.Serialize overloads accepting JsonSerializerContext don't support unspeakable types. runtime#84260
  • Deserializing and serializing enums with strings are not AOT-safe Provide trim/AOT-safe mechanism to (de)serialize enums from strings with JSON source-gen runtime#79311

Other

The following areas do not have AoT support at the moment.

• Authentication (JwtBearer coming soon)
• SignalR
• MVC
• Blazor Server

See also https://learn.microsoft.com/dotnet/core/deploying/native-aot/