Possible System.Diagnostics.DiagnosticSource trimming issue

[jamiewinder]

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

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[tarekgh]

@agocke, @MichalStrehovsky I confirmed the issue reproduce. The constructor exists in the ActivitySource class System.Diagnostics.ActivitySource..ctor(System.String). Note, this constructor didn't exist in net8 version of the library. Are we performing the trimming against the assembly shipped with the framework?

The ILLink.Substitutions.xml in both net8 and net9 versions of System.Diagnostics.DiagnosticSource don't have any section for ActivitySource type. Could you please have a look?

[tarekgh]

Making the app target net9 makes the issue disappear.

[jkotas]

Looks like a dup of #108909 and related issues.

The conflicts between inbox assemblies and OOB packages are not resolved correctly for AOT compilation. The inbox assembly wins even when the OOB packages provides higher version.

[tarekgh]

I hope we can service the fix of this issue on net8 if possible. My understanding is that OpenTelemetry started to take dependency on System.Diagnostics.DiagnosticSource v9.0. This will make net8 users broken if they want to build as AOT.

CC @reyang @noahfalk

[jamiewinder]

@tarekgh This is indeed how I first encountered the issue before reducing it down to the above. It isn't just OpenTelemetry either, a lot of the recently released Microsoft 9.x libraries now have this dependency, rendering them unusable with AOT and .NET 8.