I'm testing out Core Data batch insert. The performance is amazing!! Data gets imported in a just a couple hundreds of milliseconds. New rows are inserted and existing rows are updated. I ran into 1 problem though.... If the unique constraint is set with multiple attributes, batch insert will fail. Below is the call stack of the failed operation: 2020-10-06 00:05:44.900901-0700 TestHostingApp[17605:1541912] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'error in batch insertion: Error Domain=NSCocoaErrorDomain Code=134050 "(null)" UserInfo={NSExceptionOmitCallstacks=true, _NSCoreDataOptimisticLockingFailureConflictsKey=()}' \*\*\* First throw call stack: ( 0   CoreFoundation                      0x00007fff2043a126 __exceptionPreprocess + 242 1   libobjc.A.dylib                     0x00007fff20177f78 objc_exception_throw + 48 2   CoreFoundation                      0x00007fff20439f4f +[NSException raise:format:] + 0 3   Foundation                          0x00007fff207881ca -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191 4   SchedKit2_Tests                     0x0000000104fb85a7 -[NSManagedObjectContext(SchedBatchInsert) batchInsertWithEntityName:objects:] + 391 5   SchedKit2_Tests                     0x0000000104fb3194 __92+[BatchImport importEntityWithName:confID:batchSize:context:queue:formatHandler:completion:]_block_invoke_2.73 + 180 6   CoreData                            0x00007fff25109933 developerSubmittedBlockToNSManagedObjectContextPerform + 154 7   libdispatch.dylib                   0x00007fff20106534 _dispatch_client_callout + 8 8   libdispatch.dylib                   0x00007fff2010c425 _dispatch_lane_serial_drain + 715 9   libdispatch.dylib                   0x00007fff2010cfa0 _dispatch_lane_invoke + 403 10  libdispatch.dylib                   0x00007fff20117591 _dispatch_workloop_worker_thread + 782 11  libsystem_pthread.dylib             0x00007fff5dcd8a3d _pthread_wqthread + 290 12  libsystem_pthread.dylib             0x00007fff5dcd7b77 start_wqthread + 15 ) libc++abi.dylib: terminating with uncaught exception of type NSException My entity has this constrain configuration: Constraints: eventID,sessionID The context where batch insert operation has mergeByPropertyObjectTrumpMergePolicy policy set. Is this a known limitation? (i.e. I can only set unique constraint on 1 attribute in order to have batch insert work correctly?)

Question about "Sign in with Apple". Can 2 apps from 2 different developer accounts (hence, 2 different team ID) share authentications? In other words, can I get consistent user ID from 2 different app under 2 different developer account? Is there a way to configure that from developer portal? Thanks Bill

Hi all! I am using Swift Playgrounds 4.5.1 on Mac and iPad. When I create new book, they both create new book with Swift 5.9 (instead of Swift 5.10). Is this a bug? The release notes says since 4.5.0 the Swift version has been upgraded to 5.10. Thanks B