code: func (b *lowBuilder) searchOwner() (owner *serverconfig.Owner, err error) {
  	if b.high.Identity == "" {
  		return nil, errNoOwner
  	}
  	if b.high.IdentitySecretRing == "" {
  		return nil, errNoOwner
  	}
  	return &serverconfig.Owner{
  		Identity:    b.high.Identity,
  		SecringFile: b.high.IdentitySecretRing,
  	}, nil
  }
docs: // Error is errNoOwner if no identity configured