ios – 获取警告设置自定义协议的委托

Sending 'MyCustomViewControllerClass *const __strong' to parameter of incompatible type 'id<NSFileManagerDelegate>'

项目构建和运行,一切正常,减去警告.如果我添加< NSFileManagerDelegate>我的自定义类警告消失了.我错过了什么,或者这是Xcode(6 beta)中的错误？代码是设置协议/委托的标准代码,但无论如何我都会发布它…

SomeSecondClass.h

#import <UIKit/UIKit>

@class SomeSecondCustomViewController;

@protocol SomeSecondCustomViewControllerDelegate <NSObject>
- (void)doThisForMe
@end

@interface SomeSecondCustomViewController : UIViewController

@property (weak,nonatomic) id <SomeSecondCustomViewControllerDelegate> delegate;

@end

SomeSecondClass.m

@interface SomeSecondViewController ()
…stuff

-(void)someMethod {

    [self.delegate doThisForMe];
}

@end

CustomClass.h

#import <UIKit/UIKit.h>
#import “ SomeSecondViewController.h”

@interface MyCustomViewController : UIViewController <SomeSecondCustomViewControllerDelegate>
//adding on <NSFileManagerDelegate> removes the warning...
@end

CustomClass.h

...standard stuff...

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([[segue identifier] isEqualToString:@"MySegue"]) {

         //this is where the warning happens on "self"
         [segue.destinationViewController setDelegate:self];

    }
}


- (void)doThisForMe {

   //doing some stuff...

}
@end

我已经打开了之前没有警告的项目,现在出现了相同的警告.我想知道这是否是一个Xcode问题？