+ (NSManagedObjectContext *) MR_defaultContext
{
    @synchronized(self) {
        NSAssert(MagicalRecordDefaultContext != nil,@"Default context is nil! Did you forget to initialize the Core Data Stack?");
        return MagicalRecordDefaultContext;
    }
}

我已经评论过我以前的所有测试,并且这两个测试都显示出相同的行为：

#import <XCTest/XCTest.h>
 
@interface BadTests : XCTestCase
 
@end
 
@implementation BadTests
 
- (void)setUp {
    [super setUp];
}
 
- (void)tearDown {
    [super tearDown];
}
 
- (void)testSanity {
    XCTAssert(1 == 1);
}
 
@end

和

#import <XCTest/XCTest.h>
#import <MagicalRecord/MagicalRecord.h>
 
@interface BadTests : XCTestCase
 
@end
 
@implementation BadTests
 
- (void)setUp {
    [super setUp];
    NSLog(@"*** USING IN MEMORY STORE ***");
    [MagicalRecord setLoggingLevel:MagicalRecordLoggingLevelDebug];
    [MagicalRecord setupCoreDataStackWithInMemoryStore];
}
 
- (void)tearDown {
    [MagicalRecord cleanUp];
    [super tearDown];
}
 
- (void)testSanity {
    XCTAssert(1 == 1);
}
 
@end

用相同的测试恢复到Xcode 6可以解决问题.