Myujth

I am learning golang and try to debug a sample code which comes from one of my golang book. It is very strange that delve debugger is not working as expected.

As you can see in this picture, I can set break point at line 83 and continue to run program to this break point. On the left panel, I can see the variables and call stack are displayed. But when I step into next statement from that break point, the debugger seems to be stopped. All the
variables are cleared out but call stack still showing me the problem is running like picture below:

I also tried delve debugger in command line (out side vs-code), I got the same issue on the same break point.

VS-Code launch.json like below:

 // 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": "Launch",
 "type": "go",
 "request": "launch",
 "mode": "auto",
 "program": "$fileDirname",
 "env": ,
 "args": ,
 "trace": true
 
 ]

Go version: 1.10.3 windows/amd64

Delve debugger version: 1.1.0

VS-Code version: 1.29.0

Do I need other configuration?

I attach source code here, you can give a try and see what happen on your machine.

Source Code:

package main

import (
 "bufio"
 "fmt"
 "io"
 "log"
 "os"
 "path/filepath"
 "regexp"
)

func filenamesFromCmdLine() (inFilename, outFilename string, err error) os.Args[1] == "--help") 
 err = fmt.Errorf("Usage: %s [<]infile.txt [>]outfile.txt", filepath.Base(os.Args[0]))
 return "", "", err
 

 if len(os.Args) > 1 
 inFilename = os.Args[1]
 
 if len(os.Args) > 2 
 outFilename = os.Args[2]
 
 if inFilename != "" && inFilename == outFilename 
 log.Fatal("won't overwrite the infile")
 

 return inFilename, outFilename, nil


func americanise(inFile io.Reader, outFile io.Writer) (err error) 

 reader := bufio.NewReader(inFile)
 writer := bufio.NewWriter(outFile)
 defer func() 
 if err == nil 
 err = writer.Flush()
 
 ()

 var replacer func(string) string

 wordRx := regexp.MustCompile("[A-Za-z]+")
 eof := false
 for !eof 
 var line string
 line, err = reader.ReadString('n')
 if err == io.EOF 
 err = nil
 eof = true
 else if err != nil 
 return err
 
 line = wordRx.ReplaceAllStringFunc(line, replacer)
 if _, err = writer.WriteString(line); err != nil 
 return err
 
 

 return nil


func main() 
 inFilename, outFilename, err := filenamesFromCmdLine()
 if err != nil 
 fmt.Println(err)
 os.Exit(0)
 

 //why we initialize them to stdin and stdout?
 //the file object has been set to os.Stdin and os.Stdout
 inFile, outFile := os.Stdin, os.Stdout

 if inFilename != "" 
 //os.Open() returns *os.File that can be used for reading the file.
 if inFile, err = os.Open(inFilename); err != nil 
 log.Fatal(err)
 
 //defer inFile.Close()
 

 if outFilename != "" 
 //create a new file or truncate to zero length for existing file
 if outFile, err = os.Create(outFilename); err != nil 
 log.Fatal(err)
 
 defer outFile.Close()
 

 if err = americanise(inFile, outFile); err != nil 
 log.Fatal(err)
 

Unfortunately Delve in VS-Code does not handle "GoTo Next Step" well when you are executing multiple go routines with each waiting for going to Next Step. One workaround I use is that I put another debug point where I want the debugging to stop and then select "Continue" option.

I'm not sure about your situation but there was a bug in vscode-go previous versions. Does your version 0.7.0 ?