workflow

1. start

   var errs errors.Err
   var err error

2. error occurs in come code somewhere

   err = someFunc()

3. capture and wrap the error to add context

   if nil != err {
       errs = errors.Wrap(err, 0, "the call to someFunc to do some particular work failed")
   }

4. do some more work, repeat

   // if someFunc failed do a thing
   if nil != err {
       errs = errors.Wrap(err, 0, "the call to someFunc while trying to do allTheWork failed")
       err = buidSome()
       if nil != err {
           errs = errors.Wrap(err, 0, "could not build 'some'")
       }
   }

5. return standard error

   func allTheStuff() error {
       var errs errors.Err
       var err error
   
       err = someFunc()
       // if someFunc failed do a thing
       if nil != err {
           errs = errors.Wrap(err, 0, "the call to someFunc while trying to do allTheWork failed")
           err = buidSome()
           if nil != err {
               errs = errors.Wrap(err, FailedToBuild, "could not build 'some'")
           }
       }
       return errs
   }

6. capture and handle

   func main() {
       errs := allTheStuff()
       for _, err := range errs.(errors.Err) {
           switch err.Err().(type) {
           case BuildErr:
                  log.Fatalf("%+v", errs)
           }
       }
       log.Errorf("%+v", errs)
   }