How to read input when debugging GO in Visual Studio Code?

Question

I want to debug a Go program in Visual Studio Code 1.24.0 which goes like this:

package main

import (
   "fmt"
)

func main() {
 fmt.Println("Hello World")
 var input int
 fmt.Scanf("%d", &input)
 fmt.Printf("Hello %v", input)
}

When start debugging, the program waits for input. I tried giving input via Debug Console, but it didn't work. Properties like externalConsole don't seem to work in launch.json for Go. Any inputs?

Answer 1

I'm happy to share that a more usable solution (It automatically runs the task before launching) is found.

...

launch.json:

{
    // 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": "Connect to server",
            "type": "go",
            "request": "attach",
            "preLaunchTask": "delve",
            "mode": "remote",
            "remotePath": "${workspaceFolder}",
            "port": 23456,
            "host": "127.0.0.1",
            "cwd": "${workspaceFolder}"
        }
    ]
}

And
tasks.json:

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "label": "delve",
            "type": "shell",
            "command": "dlv debug --headless --listen=:23456 --api-version=2 \"${workspaceFolder}\"",
            "isBackground": true,
            "presentation": {
                "focus": true,
                "panel": "dedicated",
                "clear": false
            },
            "group": {
                "kind": "build",
                "isDefault": true
            },
            "problemMatcher": {
                "pattern": {
                    "regexp": ""
                },
                "background": {
                    "activeOnStart": true,
                    "beginsPattern": {
                        "regexp": ".*"
                    },
                    "endsPattern": {
                        "regexp": ".*server listening.*"
                    }
                }
            }
        }
    ]
}

It expects you are working with a go.mod since delve also looks for it to debug the directory.

Answer 2

In the same Issue HowieLiuX shared a sinmpler solution that works for me:

In tasks.json:

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "label": "echo",
            "type": "shell",
            "command": "cd ${fileDirname} && dlv debug --headless --listen=:2345 --log --api-version=2",
            "problemMatcher": [],
            "group": {
                "kind": "build",
                "isDefault": true
            }
        }
    ]
}

I, however, had to change command to:

"command": "dlv debug --headless --listen=:2345 --log --api-version=2",

since I'm running through powershell.

Then in launch.json

{
    // 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": "Connect to server",
            "type": "go",
            "request": "launch",
            "mode": "remote",
            "remotePath": "${fileDirname}",
            "port": 2345,
            "host": "127.0.0.1",
            "program": "${fileDirname}",
            "env": {},
            "args": []
        }
    ]
}

First run the task then debug.