src/client/auth/auth.go
func IsErrInvalidPrincipal(err error) bool {
	if err == nil {
		return false
	}
	return strings.Contains(err.Error(), "invalid principal \"") &&
		strings.Contains(err.Error(), "\"; must start with one of \"pipeline:\", \"github:\", or \"robot:\", or have no \":\"")
}
func IsErrInvalidPrincipal(err error) bool {
	if err == nil {
		return false
	}
	return strings.Contains(err.Error(), "invalid principal \"") &&
		strings.Contains(err.Error(), "\"; must start with one of \"pipeline:\", \"github:\", or \"robot:\", or have no \":\"")
}
// IsErrInvalidPrincipal returns true if 'err' is an ErrInvalidPrincipal