Mac Sonoma 14.4.1 with arm arch fails to start x64 debug

[Sh18RW]

Environment data

dotnet --info output:

.NET SDK:
 Version:           9.0.102
 Commit:            cb83cd4923
 Workload version:  9.0.100-manifests.7c7c79ca
 MSBuild version:   17.12.18+ed8c6aec5

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  14.4
 OS Platform: Darwin
 RID:         osx-x64
 Base Path:   /usr/local/share/dotnet/x64/sdk/9.0.102/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.1
  Architecture: x64
  Commit:       c8acea2262

.NET SDKs installed:
  9.0.100-preview.1.24101.2 [/usr/local/share/dotnet/x64/sdk]
  9.0.102 [/usr/local/share/dotnet/x64/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.0-preview.1.24081.5 [/usr/local/share/dotnet/x64/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.1 [/usr/local/share/dotnet/x64/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.0-preview.1.24080.9 [/usr/local/share/dotnet/x64/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.1 [/usr/local/share/dotnet/x64/shared/Microsoft.NETCore.App]

Other architectures found:
  arm64 [/usr/local/share/dotnet]
    registered at [/etc/dotnet/install_location_arm64]

Environment variables:
  DOTNET_ROOT_ARM   [/usr/local/share/dotnet]
  DOTNET_ROOT_X64   [/usr/local/share/dotnet/x64]

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

VS Code version: 1.96.4 (Universal)
C# Extension version: 2.61.28

Steps to reproduce

Set a launch option

{
            "name": "Mac x64 Server",
            "type": "coreclr",
            "request": "launch",
            "program": "/usr/local/share/dotnet/x64/dotnet",
            "args": ["${workspaceFolder}/bin/Content.Server/Content.Server.dll"],
            "console": "integratedTerminal",
            "stopAtEntry": false,
            "targetArchitecture": "x86_64",
        },

and start to debug.

Behavior

I need to switch from ARM to x64 for my .NET project. The project has been migrated from .NET 8 to .NET 9, and now I need to use version 9. However, for some reason, the x64 SDK is not working properly for debugging, and it can only be used for running the project. ARM versions are working fine (but I cannot use it).
So if I start debug, it begins to execute, but suddenly stops without any message.
Also the debug console contains

------------------------------------------------------------------------------
You may only use the Microsoft Visual Studio .NET/C/C++ Debugger (vsdbg) with
Visual Studio Code, Visual Studio or Visual Studio for Mac software to help you
develop and test your applications.
------------------------------------------------------------------------------
dotnet (85191): Loaded '/usr/local/share/dotnet/x64/shared/Microsoft.NETCore.App/9.0.1/System.Private.CoreLib.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
The program '[85191] dotnet' has exited with code 0 (0x0).

I am not sure if it is a .NET 9 issue, but I have not been able to find anything similar. Perhaps it is just a problem on my end for some reason.

[Sh18RW]

dotnet/sdk#43206
I found...

[gregg-miskelly]

What is printed to the integrated terminal?

[Sh18RW]

What is printed to the integrated terminal?

There is nothing.

[gregg-miskelly]

If you try running /usr/local/share/dotnet/x64/dotnet **insert-workspace-folder-path-here**/bin/Content.Server/Content.Server.dll from a terminal do you see anything?

From a debugger perspective, there isn't an obvious problem -- it looks like the target process just decides to exit for some reason. I don't know why that reason isn't printed to the terminal, but probably worth trying from a real console.

[Sh18RW]

The program started. I also tried using Rider, but the same problem occurred. If I start debugging, it stops working. However, just running the code works fine.

[gregg-miskelly]

Interesting. Sounds like maybe there is something incompatible between Rossetta emulation of the very low-level debugging primitives the runtime uses.

A few ideas to troubleshoot next:

1. Can you reproduce this problem with a "Hello World" .NET 9 ASP.NET Core project? (I am assuming your real project is ASP.NET Core, if not, replace with whatever project type you are using)
2. Can you try turning on 'debug runtime event tracing' (see below)
3. If this isn't too hard to try -- does the problem happen if you target .NET 8 instead of .NET 9?

launch.json setting to turn on logging:

"logging": {
                "diagnosticsLog": {
                    "debugRuntimeEventTracing": true
                }
            }

[Sh18RW]

1-2. I created an empty APS.NET project:

Using launch settings from '/Users/petrsmirnov/Projects/sandbox/WebApplication21/Properties/launchSettings.json' [Profile 'https']...
[Debug Runtime Event] DBI Callback -- CreateProcess(Process:00007F842E07AE28)
[Debug Runtime Event] DBI Callback -- CreateAppDomain(Process:00007F842E07AE28, AppDomain:00007F842D8250F8)
[Debug Runtime Event] DBI Callback -- LoadAssembly(AppDomain:00007F842D8250F8, Assembly:00007F842DA607C8)
[Debug Runtime Event] DBI Callback -- LoadModule(AppDomain:00007F842D8250F8, Module:00007F842D8242C8)
WebApplication21.dll (28998): Loaded '/usr/local/share/dotnet/x64/shared/Microsoft.NETCore.App/9.0.1/System.Private.CoreLib.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
[Debug Runtime Event] DBI Callback -- NameChange(AppDomain:00007F842D8250F8, Thread:0000000000000000)
[Debug Runtime Event] DBI Callback -- CreateThread(AppDomain:00007F842D8250F8, Thread:00007F842CF514B8)

3. If I build with dotnet build -p:TargetFramwork=net8.0.12, debugging starts.

[gregg-miskelly]

Thanks! With your information I was able to reproduce this as well. I couldn't find an issue for it in the .NET Runtime repo, so I opened one: dotnet/runtime#112137

[Sh18RW]

Thanks!

[Sh18RW]

The issue no longer reproduces, it is more likely Rosetta has fixed.