Enabling C# debugger logging

Here is how to enable additional logging for the VS Code C# debugger to help troubleshoot problems.

VS Code Settings

The C# debugger exposes several logging setting via a Visual Studio Code Setting. To modify them:

1. Open up the VS Code settings editor (File->Preferences->Settings).
2. Enter 'diagnosticsLog' into the search bar
3. Navigate to 'Extensions->C#->Debugger' using the settings tree
4. Enable the required setting. The most commonly used logging setting is 'Protocol Messages'.

Using launch.json

If you have VS Code configured using a launch.json file with "type": "coreclr" or "type": "clr", then you can configure logging using launch configuration properties. Here is an example of the new sections to add to launch.json:

    "configurations": [
        {
            "type": "coreclr",
            "...": "...",
            "logging": {
                "diagnosticsLog": {
                    "protocolMessages": true
                }
            }
        },
        { "...": "..." }
    ]

When this is enabled, logging will be sent to the VS Code Debug Console where you can copy/paste the relevant sections.

Full Method

If you are dealing with a problem that happens either very early on during debugger startup, or a problem where the debugger is crashing, it can be helpful to run the debugger (vsdbg-ui) in the console.

To do this:

1. Open up a terminal (command prompt) window
2. Change to the directory of the debugger. (NOTE: if you are using VS Code Insiders, change .vscode to .vscode-insiders)
   • Linux/macOS: cd ~/.vscode/extensions/ms-dotnettools.csharp-<insert-version-here>/.debugger
   • Windows: cd /d C:\Users\<your-username>\.vscode\extensions\ms-dotnettools.csharp-<insert-version-here>\.debugger
3. Run vsdbg-ui: ./vsdbg-ui --server --consoleLogging
4. Go back to VS Code and open your .vscode\launch.json file.
5. Go to the section for of launch.json for your current launch configuration and add: "debugServer": 4711
6. Debug as normal
7. When the problem happens, look at what is printed into the terminal.

Example launch.json configuration:

{
   "version": "0.2.0",
   "configurations": [
        {
            "debugServer": 4711,
            "name": ".NET Core Launch (console)",
            "...": "...",
        },
        { "...": "..." }
    ]
}