Issues with stack trace .NET SDK 8.0.300+

[rsandbach]

I am having an issue where some exceptions in a component are missing the file and line number in the stack trace. This appears to have started when building with 8.0.300. If I revert the build to use 8.0.204 the line numbers are shown, even when using the latest runtime versions.

This is only happening for exceptions that occur in BuildRenderTree of the component.

If built with mcr.microsoft.com/dotnet/sdk:8.0.204-alpine3.19

2025-01-27 11:16:54 fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
2025-01-27 11:16:54       Unhandled exception in circuit 'i2I_Y0qUm6gBksoigcgqJSPEYSz3QMe-6ouymZN-To8'.
2025-01-27 11:16:54       System.NullReferenceException: Object reference not set to an instance of an object.
2025-01-27 11:16:54          at DET.Components.Pages.Home.BuildRenderTree(RenderTreeBuilder __builder) in /src/Components/Pages/Home.razor:line 2
2025-01-27 11:16:54          at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException)
2025-01-27 11:17:06 fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
2025-01-27 11:17:06       Unhandled exception in circuit 'zyNKsYQt2rxNFdPFr4qGh8xo_b7C0RWtYSPJF0N_6Z4'.
2025-01-27 11:17:06       System.NullReferenceException: Code Block
2025-01-27 11:17:06          at DET.Components.Pages.Home.ThrowFromCodeBlock() in /src/Components/Pages/Home.razor:line 14
2025-01-27 11:17:06          at Microsoft.AspNetCore.Components.EventCallbackWorkItem.InvokeAsync[T](MulticastDelegate delegate, T arg)
2025-01-27 11:17:06          at Microsoft.AspNetCore.Components.ComponentBase.Microsoft.AspNetCore.Components.IHandleEvent.HandleEventAsync(EventCallbackWorkItem callback, Object arg)
2025-01-27 11:17:06          at Microsoft.AspNetCore.Components.RenderTree.Renderer.DispatchEventAsync(UInt64 eventHandlerId, EventFieldInfo fieldInfo, EventArgs eventArgs, Boolean waitForQuiescence)

If built with mcr.microsoft.com/dotnet/sdk:8.0.300-alpine3.19 or newer.

2025-01-27 11:18:52 fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
2025-01-27 11:18:52       Unhandled exception in circuit 'ERSqkhER3YOEqnXBatXy4zsnceX4_udvSE7zmyJmLPI'.
2025-01-27 11:18:52       System.NullReferenceException: Object reference not set to an instance of an object.
2025-01-27 11:18:52          at DET.Components.Pages.Home.BuildRenderTree(RenderTreeBuilder __builder)
2025-01-27 11:18:52          at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException)
2025-01-27 11:18:58 fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
2025-01-27 11:18:58       Unhandled exception in circuit 'C1sB_s_mokVO1B4Ghpn1ff_iloZ20f48RuZXt5s3PKQ'.
2025-01-27 11:18:58       System.NullReferenceException: Code Block
2025-01-27 11:18:58          at DET.Components.Pages.Home.ThrowFromCodeBlock() in /src/Components/Pages/Home.razor:line 14
2025-01-27 11:18:58          at Microsoft.AspNetCore.Components.EventCallbackWorkItem.InvokeAsync[T](MulticastDelegate delegate, T arg)
2025-01-27 11:18:58          at Microsoft.AspNetCore.Components.ComponentBase.Microsoft.AspNetCore.Components.IHandleEvent.HandleEventAsync(EventCallbackWorkItem callback, Object arg)
2025-01-27 11:18:58          at Microsoft.AspNetCore.Components.RenderTree.Renderer.DispatchEventAsync(UInt64 eventHandlerId, EventFieldInfo fieldInfo, EventArgs eventArgs, Boolean waitForQuiescence)

This is my example component:

@page "/"
@test.Name
<button @onclick="ThrowFromRenderTree">Render Tree Exception</button>
<button @onclick="ThrowFromCodeBlock">Codeblock Exception</button>

@code {
    void ThrowFromRenderTree()
    {
        test = null;
    }

    void ThrowFromCodeBlock()
    {
        throw new NullReferenceException("Code Block");
    }

    TestClass? test  = new TestClass { Name = "Testing" };

    class TestClass
    {
        public string? Name { get; set; }
    }
}

I'm trying to understand why this is. I've tried disabling optimizations and that does not seem to change the behavior.

[rsandbach]

This seems to be caused by changes made to how the #line directives are added when generating the code for razor components.

See dotnet/razor#11432.