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我在 CoreData 版本迁移中遇到了一个奇怪的错误。它崩溃了，我完全被难住了。我在我的 xcdatamodel 版本 2 中为一个子实体添加了两个新属性，并将其设置为当前版本。创建持久存储协调器的代码如下所示：

 NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"MyModel" withExtension:@"momd"];
    self.mainModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    self.mainQueueManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
    self.persistentStoreCoordinator = [self storeCoordinatorForDB:@"MyDB.sqlite" objectModel:self.mainModel managedObjectContext:self.mainQueueManagedObjectContext];

- (NSPersistentStoreCoordinator *)storeCoordinatorForDB:(NSString *)dbName objectModel:(NSManagedObjectModel *)model managedObjectContext:(NSManagedObjectContext *)moc {
    NSFileManager *fm = [NSFileManager defaultManager];
    NSURL *storeURL = [[fm URLsForDirectory:NSApplicationSupportDirectory
                              inDomains:NSUserDomainMask] lastObject];
    if (!storeURL) {
        return nil;
    }
    else {
        NSError *createError = nil;
        BOOL createSuccess = [fm createDirectoryAtURL:storeURL withIntermediateDirectories:YES attributes:nil error:&createError];
        if (!createSuccess) {
            NSLog(@"Dir creation error: %@", createError);
        }
    }
    storeURL = [storeURL URLByAppendingPathComponent:dbName];
    NSURL *mainBundleDBURL = [[[NSBundle mainBundle] bundleURL] URLByAppendingPathComponent:dbName];
    NSError *copyError = nil;
    BOOL copySuccess = [fm copyItemAtURL:mainBundleDBURL toURL:storeURL error:&copyError];
    if (!copySuccess) {
        NSLog(@"File copy error: %@", copyError);
    }

    NSError *error = nil;
    NSPersistentStoreCoordinator *coordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:model];
    moc.persistentStoreCoordinator = coordinator;
    NSPersistentStore *ps = [coordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:@{
                       NSMigratePersistentStoresAutomaticallyOption:@(YES),
                             NSInferMappingModelAutomaticallyOption:@(YES)
                             } error:&error];
    if (!ps) {
        NSLog(@"Unresolved error adding persistent store: %@", error);
        return nil;
    }
    return coordinator;
}

MyDB.sqlite 是来自先前版本的 xcdatamodel 的预置 CoreData 文件。

这导致 EXC_BAD_ACCESS 在一个（据我所知）绝对虚假的地址，例如。0x0 或 0x16)

结果堆栈跟踪是：

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00000000
Crashed Thread:  0

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   libobjc.A.dylib                 0x3b2f95d6 objc_msgSend + 22
1   CoreData                        0x333e5274 -[NSFetchedPropertyDescription copyWithZone:] + 140
2   CoreData                        0x333d8f62 -[NSEntityDescription copyWithZone:] + 682
3   CoreData                        0x333d8e70 -[NSEntityDescription copyWithZone:] + 440
4   CoreData                        0x3340f4a8 -[NSManagedObjectModel copyWithZone:] + 340
5   CoreData                        0x3341d20e -[NSMigrationManager initWithSourceModel:destinationModel:] + 178
6   CoreData                        0x3346dc5e -[NSStoreMigrationPolicy managerForSourceModel:destinationModel:error:] + 390
7   CoreData                        0x3346f060 -[NSStoreMigrationPolicy(InternalMethods) _gatherDataAndPerformMigration:] + 1596
8   CoreData                        0x3339235c -[NSPersistentStoreCoordinator addPersistentStoreWithType:configuration:URL:options:error:] + 3340
9   ActorsNetwork                   0x000ba072 -[DataStore storeCoordinatorForDB:objectModel:managedObjectContext:] (DataStore.m:69)

有人知道发生了什么或有用的提示如何调试吗？我已经尝试过仪器分配，但没有进一步。

[已解决] 有点。我在模型中有一个获取的属性定义。删除修复了导入崩溃的问题。

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