Go errors with stack trace

main.go

package main

import (
	"bytes"
	"errors"
	"fmt"
	"runtime"
)

type AppError struct {
	trace string
	err   error
}

// Error returns the string representation of the error message.
func (e *AppError) Error() string {
	return fmt.Sprintf("%s\n%s", e.trace, e.err)
}

func (e *AppError) Unwrap() error {
	return e.err
}

// StackTrace returns the string representation of the error stack trace,
// includeTrace appends caller pcs frames to each error message if possible.
func (e *AppError) StackTrace() (string, error) {
	var buf bytes.Buffer

	if e.trace != "" {
		if _, err := fmt.Fprintf(&buf, "%s", e.trace); err != nil {
			return "", err
		}
	}

	if e.err == nil {
		return buf.String(), nil
	}

	var next *AppError
	if errors.As(e.err, &next) {
		stackTrace, err := next.StackTrace()
		if err != nil {
			return "", err
		}

		buf.WriteString(fmt.Sprintf("\n%s", stackTrace))
	} else {
		return fmt.Sprintf("%s\n%s", buf.String(), e.err), nil
	}

	return buf.String(), nil
}

func AppenStackTrace(err error) *AppError {
	if err == nil {
		panic("nil error provided")
	}

	var buf bytes.Buffer

	frame := getFrame(2)

	fmt.Fprintf(&buf, "%s", frame.File)
	fmt.Fprintf(&buf, ":%d", frame.Line)
	fmt.Fprintf(&buf, " %s", frame.Function)

	return &AppError{
		err:   err,
		trace: buf.String(),
	}
}

func main() {
	err := AppenStackTrace(testOne())
	fmt.Printf("%s", err)

	t, _ := err.StackTrace()
	fmt.Printf("\n\n%s", t)
}

func testOne() error {
	return fmt.Errorf("testOne: %w", AppenStackTrace(testTwo()))

}

func testTwo() error {
	return fmt.Errorf("testTwo: %w", AppenStackTrace(testThree()))
}

func testThree() error {
	return AppenStackTrace(fmt.Errorf("internal error"))
}

func getFrame(calldepth int) *runtime.Frame {
	pc, file, line, ok := runtime.Caller(calldepth)
	if !ok {
		return nil
	}

	frame := &runtime.Frame{
		PC:   pc,
		File: file,
		Line: line,
	}

	funcForPc := runtime.FuncForPC(pc)
	if funcForPc != nil {
		frame.Func = funcForPc
		frame.Function = funcForPc.Name()
		frame.Entry = funcForPc.Entry()
	}

	return frame
}

Run this example on The Go Playground