如何使用“log/slog”记录错误

package main

import (
    "fmt"
    "log/slog"
    "os"
)

func demoFunction() error {
    return fmt.Errorf("oh no: %v", 123)
}

func main() {
    logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
    slog.SetDefault(logger)

    slog.Info("info demo", "count", 3)
    slog.Warn("warn demo", slog.String("somekey", "somevalue"))
    slog.Error("error demo", slog.Int("someintkey", 123))
    err := demoFunction()
    if err != nil {
        // Here I'm logging the error as a string, but I presume there is a better way
        // possibly that will log stack trace info as well.
        slog.Error("the demo function got an error.", slog.String("error", err.Error()))
    }
}

func ErrAttr(err error) slog.Attr {
    return slog.Any("error", err)
}