Function Wrapf

errors.go:201–213

Wrapf returns an error annotating err with a stack trace at the point Wrapf is called, and the format specifier. If err is nil, Wrapf returns nil.

(err error, format string, args ...interface{})

// at the point Wrapf is called, and the format specifier.
// If err is nil, Wrapf returns nil.
func Wrapf(err error, format string, args ...interface{}) error {
	if err == nil {
		return nil
	}
	err = &withMessage{
		cause: err,
		msg:   fmt.Sprintf(format, args...),
	}
	return &withStack{
		err,
		callers(),
	}
}

// WithMessage annotates err with a new message.
// If err is nil, WithMessage returns nil.