package service import ( "github.com/pkg/errors" ) var ErrSomething = errors.New("something") type MyError struct { Payload string `json:"payload"` err error } func (e *MyError) Error() string { return e.Payload + ": " + e.err.Error() } func (e *MyError) Unwrap() error { return e.err } func NewMyError(msg string, err error) error { return &MyError{Payload: msg, err: err} }