How can I configure Visual Studio Code to run/debug .NET (dotnet) Core from the Windows Subsystem for Linux (WSL)?

Question

I've installed .NET Core 2.2 in the Windows Subsystem for Linux (WSL) and created a new project. I've also installed the C# extension for Visual Studio Code and the syntax highlighting and IntelliSense seems to be working.

However, when I try to use the debugger, things stop working. Here's a step by step of what I've tried to do to configure it.

Here's my launch.json file:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": ".NET Core Launch (console)",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            "program": "${workspaceFolder}/bin/Debug/netcoreapp2.2/CodeCore.dll",
            "args": [],
            "cwd": "${workspaceFolder}",
            "console": "internalConsole",
            "stopAtEntry": false,
            "internalConsoleOptions": "openOnSessionStart"
        },
        {
            "name": ".NET Core Launch (web)",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            "program": "${workspaceFolder}/bin/Debug/netcoreapp2.2/CodeCore.dll",
            "args": [],
            "cwd": "${workspaceFolder}",
            "stopAtEntry": false,
            "internalConsoleOptions": "openOnSessionStart",
            "launchBrowser": {
                "enabled": true,
                "args": "${auto-detect-url}",
                "windows": {
                    "command": "cmd.exe",
                    "args": "/C start ${auto-detect-url}"
                },
                "osx": {
                    "command": "open"
                },
                "linux": {
                    "command": "xdg-open"
                }
            },
            "env": {
                "ASPNETCORE_ENVIRONMENT": "Development"
            },
            "sourceFileMap": {
                "/Views": "${workspaceFolder}/Views"
            }
        },
        {
            "name": ".NET Core Attach",
            "type": "coreclr",
            "request": "attach",
            "processId": "${command:pickProcess}"
        }
    ]
}

And my tasks.json file:

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "label": "build",
            "command": "dotnet build",
            "type": "shell",
            "group": "build",
            "presentation": {
                "reveal": "silent"
            },
            "problemMatcher": "$msCompile"
        }
    ]
}

My directory structure:

But when I click the "Start Debugging" button I get the following error:

launch: program " does not exist

Answer 1

There is a great article on GitHub regarding the subject - Windows Subsystem for Linux.

To cut a long story short, you need to first verify your version after the Windows 10 Creators Update:

~$ cat /etc/os-release  | grep  -i version
VERSION="16.04.2 LTS (Xenial Xerus)"
VERSION_ID="16.04"
VERSION_CODENAME=xenial

Notice the following:

If you had upgraded to Windows Creators update and already had WSL installed, you might still have Ubuntu 14 in the WSL. If the version is 14, run the following commands in a cmd prompt to reinstall and update WSL.

lxrun /uninstall /full
lxrun /install

Download the debugger:

sudo apt-get install unzip
curl -sSL https://aka.ms/getvsdbgsh | bash /dev/stdin -v latest -l ~/vsdbg

The debugger will be installed at ~/vsdbg/vsdbg. It is the debuggerPath.

Sample launch.json configuration for launch:

  {
           "name": ".NET Core WSL Launch",
           "type": "coreclr",
           "request": "launch",
           "preLaunchTask": "publish",
           "program": "/mnt/c/temp/dotnetapps/wslApp/bin/publish/wslApp.dll",
           "args": [],
           "cwd": "/mnt/c/temp/dotnetapps/wslApp",
           "stopAtEntry": false,
           "console": "internalConsole",
           "pipeTransport": {
               "pipeCwd": "${workspaceRoot}",
               "pipeProgram": "bash.exe",
               "pipeArgs": [ "-c" ],
               "debuggerPath": "~/vsdbg/vsdbg"
           }
       }

Please note:

• /.vscode/launch.json: This provides an array of different configurations you can use to launch your application. There is a drop down in the Debug view for selecting which configuration is active.
• <your-open-folder>/.vscode/tasks.json: This provides an array of different tasks, like building your application, that you can execute. Debug configurations can link to one of these tasks through the preLaunchTask property.

Sample 'publish' task for tasks.json (needed for launching):

{
    "version": "2.0.0",
    "tasks": [
        ...,
        {
            "label": "publish",
            "command": "dotnet",
            "type": "process",
            "args": [
                "publish",
                "${workspaceFolder}/wslApp.csproj",
                "-o",
                "${workspaceFolder}/bin/publish"
            ]
        }
    ]
}

Please Note:

• preLaunchTask executes dotnet publish, which builds the project on Windows. Since coreclr is cross-platform, the binary can be executed on WSL without any extra work.

• pipeProgram is set to bash.exe.

• debuggerPath points to vsdbg, the coreclr debugger.

• This will not support programs that want to read from the console.

Sample launch.json configuration for attach:

 {
           "name": ".NET Core WSL Attach",
           "type": "coreclr",
           "request": "attach",
           "processId": "${command:pickRemoteProcess}",
           "pipeTransport": {
               "pipeCwd": "${workspaceRoot}",
               "pipeProgram": "bash.exe",
               "pipeArgs": [ "-c" ],
               "debuggerPath": "~/vsdbg/vsdbg",
               "quoteArgs": true
           }
       }

Please Note:

• "processId": "${command:pickRemoteProcess}" lists the processes running on WSL using the pipe program.
• quoteArgs will quote any arguments and debugger commands with spaces if set to true.
• Use sourceFileMap to map sources if they are available in a different location than where they were built. If you build your project in Linux, make sure to add a map from the /mnt drive letters. Example: "sourceFileMap": { "/mnt/c/": "c:\\" }
• File and paths are case sensitive in Linux.