Condition condition = ((ConditionNotSatisfiedError) exception).getCondition();
ExpressionInfo expr = condition.getExpression();
String actual = renderValue(expr.getChildren().get(0).getValue());
String expected = renderValue(expr.getChildren().get(1).getValue());
ComparisonFailure failure = new SpockComparisonFailure(condition, expected, actual);
failure.setStackTrace(exception.getStackTrace());
return failure;
}