Description

The System.Diagnostics.DiagnosticSource 9.0.0 package doesn't appear to be trim safe. Specifically the ActivitySource class which appears to be missing a constructor in a published app.

If I try to call this constructor in AOT-published code, I get a MissingMethodException:

Unhandled Exception: System.MissingMethodException: Method not found: 'Void System.Diagnostics.ActivitySource..ctor(System.String)'.
at Internal.Runtime.TypeLoaderExceptionHelper.CreateMissingMethodException(ExceptionStringID, String) + 0x40
at Internal.Runtime.CompilerHelpers.ThrowHelpers.ThrowMissingMethodException(ExceptionStringID, String) + 0x9
at Program.<

$>d__0.MoveNext() + 0x15
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.StartTStateMachine + 0x3f
at Program.$(String[]) + 0x2f
at Program.(String[] args) + 0x9

Reproduction Steps

• Create a normal .NET 8 Console App with NativeAOT enabled.

• Replace Program.cs

using System.Diagnostics;

var a = new ActivitySource("test");

Console.WriteLine(a.ToString());

• Publish and run

• App successfully runs to completion. ✔️

• Install the System.Diagnostics.DiagnosticSource 9.0.0 package

• Publish and run

• Application crashes with MissingMethodException ❌

• Downgrade System.Diagnostics.DiagnosticSource 9.0.0 package to 8.0.1

• Publish and run

• App successfully runs to completion. ✔️

Expected behavior

Constructor should be callable in AOT

Actual behavior

Constructor is not callable in AOT

Regression?

8.0.1 works, 9.0.0 does not.

Known Workarounds

No response

Configuration

.NET Version: 8.0
OS: Windows
Arch: x64

Other information

No response