How to get the stack trace pointing to actual error reason

Question

Let\'s say I have some code like this:

value, err := some3rdpartylib.DoSomething()
if err != nil {
    panic(err)
}

In case err != ni

Answer 1

You can use the built-in Recover function to handle panic and print the stack trace.

From https://blog.golang.org/defer-panic-and-recover

Recover is a built-in function that regains control of a panicking goroutine. Recover is only useful inside deferred functions. During normal execution, a call to recover will return nil and have no other effect. If the current goroutine is panicking, a call to recover will capture the value given to panic and resume normal execution.

I have modified your example to use recover and eris. Eris provides a better way to handle, trace, and log errors in Go.

package main

import (
    "github.com/rotisserie/eris"
    "fmt"
)

func main() {
    value, err := DoSomething()
    defer func() {
        if r := recover(); r!= nil {
            fmt.Println(fmt.Sprintf("%+v", r))
        }
    }()
    if err != nil {
        panic(err)
    }

    fmt.Println(value)
}

func DoSomething() (string, error) {
    return "", eris.New("some error explanation here")
}

The output is:

some error explanation here
    main.DoSomething: /tmp/sandbox147128055/prog.go: 23
    main.main: /tmp/sandbox147128055/prog.go: 9
    runtime.main: /usr/local/go/src/runtime/proc.go: 203
    runtime.goexit: /usr/local/go/src/runtime/asm_amd64p32.s: 523

See it in action here https://play.golang.org/p/jgkaR42ub5q