Debugger randomly "breaking" when starting .NET Aspire application in VSCode

[mitchdenny]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When starting a .NET Aspire application in VSCode in the debugger the debugger randomly stops execution. The code is typically [External code]:

I have seen what I think is the same underlying issue occur a little bit later after the apphost/dashboard has started and execution pauses for the debugger but not code is shown anywhere. I'm not entirely sure what the cause is yet.

Expected Behavior

Debugger should only stop where we expect it to.

Steps To Reproduce

Cloned down the .NET Aspire repo and launched the WaitFor playground in VSCode under the debugger.

Exceptions (if any)

No response

.NET Version info

.NET SDK:
Version: 9.0.100
Commit: 59db016f11
Workload version: 9.0.100-manifests.3068a692
MSBuild version: 17.12.7+5b8665660

Runtime Environment:
OS Name: debian
OS Version: 12
OS Platform: Linux
RID: linux-x64
Base Path: /usr/share/dotnet/sdk/9.0.100/

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

Host:
Version: 9.0.0
Architecture: x64
Commit: 9d5a6a9aa4

.NET SDKs installed:
8.0.403 [/usr/share/dotnet/sdk]
9.0.100 [/usr/share/dotnet/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 8.0.10 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 9.0.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 8.0.10 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 9.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
None

Environment variables:
DOTNET_ROOT [/usr/share/dotnet]

global.json file:
/workspaces/aspire/global.json

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

Download .NET:
https://aka.ms/dotnet/download

Anything else?

I am using a devcontainer but not sure this is relevant.

[davidfowl]

cc @WardenGnaw

[WardenGnaw]

Can you share the debugger logs if you go to Settings (Ctrl + ,) and search for csharp.debug.logging.diagnosticsLog.protocolMessages

The output should appear in the Debug Console.

[mitchdenny]

@WardenGnaw I'll do this and once it happens again I'll share it with you.

[aaronpowell]

I've managed to create a pretty consistent scenario in which I hit this problem and did a recording of it - https://microsoftapc-my.sharepoint.com/:v:/g/personal/aapowell_microsoft_com/ETy04zg9UPpDp9YUQY8M0UcBSDWS8H-y-_F0AaLgzQEecg?e=UWOE80

I can share the logs from the C# extension too if desired

[mitchdenny]

@aaronpowell it would be good if you can share the logs. @WardenGnaw FYI

[aaronpowell]

The only logs I could find were the ones that got dumped to the debug window, is there more that can be grabbed?

[mitchdenny]

If you turn on this setting the output window should container more information:

#6719 (comment)

[WardenGnaw]

@mitchdenny Sorry, this is on my pending worklist, @aaronpowell provided an amazing video with clear instructions on how to reproduce it but haven't had the cycles to try it out.

The repro is better than just investigating the logs from the Debug Console if I can get the same issue occuring.

[aaronpowell]

@WardenGnaw https://github.com/communityToolkit/aspire is the GitHub repo that I was using in the recording, if you want to try the exact codebase

[WardenGnaw]

I was able to reproduce it, my current hunch is that the service that synchronizes all the Aspire Processes is in the middle of sending pause to other processes as it hit a breakpoint in the first debug session. Then when the UI restarts the debug session, its still emitting pause to synchronize that first breakpoint.

Also validated that this was not an issue in VS, so this should be VS Code specific.