return throwable.getMessage();
        } catch (Throwable t) {
            return String.format("Could not determine failure message for exception of type %s: %s", classNameOf(throwable), t);
        }
    }

    private static String classNameOf(Throwable failure) {
        return failure instanceof PlaceholderExceptionSupport
            ? ((PlaceholderExceptionSupport) failure).getExceptionClassName()