title: Bold fonts in UITableView cell
body: <p>I am trying to get the both the textLabel and the detailTextLabel fonts on my UITableViewCell to be bold. I easy got the textLabel to be bold like this:</p>
  
  <pre><code>- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
  {
      NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
  
      NSString *titleString = [managedObject valueForKey:@"title"];
      NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:titleString];
      [string addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:kFontSize] range:NSMakeRange(0, string.length)];
      cell.textLabel.attributedText = string;
  
      cell.detailTextLabel.text = [managedObject valueForKey:@"subtitle"];
      cell.detailTextLabel.textColor = [UIColor grayColor];
      [cell setAccessoryType:UITableViewCellAccessoryDisclosureIndicator];
  }
  </code></pre>
  
  <p>However when I try to make the detailTextLabel bold like this:</p>
  
  <pre><code>- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
  {
      NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath];
  
      NSString *titleString = [managedObject valueForKey:@"title"];
      NSMutableAttributedString *string = [[NSMutableAttributedString alloc]initWithString:titleString];
      [string addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:kFontSize] range:NSMakeRange(0, string.length)];
      cell.textLabel.attributedText = string;
  
      NSString *subtitleString = [managedObject valueForKey:@"subtitle"];
      NSMutableAttributedString *string2 = [[NSMutableAttributedString alloc]initWithString:subtitleString];
      [string2 addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:kSubFontSize] range:NSMakeRange(0, string2.length)];
      cell.detailTextLabel.attributedText = string2;
      cell.detailTextLabel.textColor = [UIColor grayColor];
      [cell setAccessoryType:UITableViewCellAccessoryDisclosureIndicator];
  }
  </code></pre>
  
  <p>This crashes the app with a SIGABRT error. </p>
  
  <p><img src="https://i.stack.imgur.com/d5EJZ.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/Q1ZCP.png" alt="enter image description here"></p>
  
  <p>Any ideas why this is happening?</p>