In Xcode Version 15.3 (15E204a) I am getting this warning: Class AKAlertImageURLProvider is implemented in both /Library/Developer/CoreSimulator/Volumes/iOS_21E213/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS17.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/AuthKit.framework/AuthKit (0x123719508) /Library/Developer/CoreSimulator/Volumes/iOS_21E213/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS17.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/AuthKitUI.framework/AuthKitUI One of the two will be used. Which one is undefined. and also objc[2875]: Class AKBiometricRatchetUtility is implemented in both /Library/Developer/CoreSimulator/Volumes/iOS_21E213/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/AuthKit.framework/AuthKit (0x12371ab10) and /Library/Developer/CoreSimulator/Volumes/iOS_21E213/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.4.simruntime/Contents/Resources/RuntimeRoot/System/Library/PrivateFrameworks/AuthKitUI.framework/AuthKitUI (0x152a1d810). One of the two will be used. Which one is undefined.

When I run this code specifying a 16TB disk: // // main.swift // walking_on_directories // // import Foundation import CommonCrypto import Foundation func sha256Checksum(forFileAtPath path: String) -> String? { // Open the file for reading guard let file = FileHandle(forReadingAtPath: path) else { return nil } defer { file.closeFile() } // Initialize the SHA-256 context var context = CC_SHA256_CTX() CC_SHA256_Init(&context) // Read the file in chunks and update the context let chunkSize = 1024 * 1024 // 1 MB while autoreleasepool(invoking: { let data = file.readData(ofLength: chunkSize) if !data.isEmpty { data.withUnsafeBytes { _ = CC_SHA256_Update(&context, $0.baseAddress, CC_LONG(data.count)) } return true } else { return false } }) {} // Finalize the context and get the checksumt var digest = [UInt8](repeating: 0, count: Int(CC_SHA256_DIGEST_LENGTH)) CC_SHA256_Final(&digest, &context) let checksum = digest.map { String(format: "%02hhx", $0) }.joined() return checksum } let startLocation = "/Volumes/16-1-23/debug_file_tracker/images" let fileManager = FileManager.default let enumerator:FileManager.DirectoryEnumerator = fileManager.enumerator(atPath:startLocation)! var count = 0 while let element = enumerator.nextObject() as? String { var existing_files_checksum = Set<String>() var isDirectory: ObjCBool = false let filePath: String = startLocation + "/" + element if fileManager.fileExists(atPath: filePath, isDirectory: &isDirectory) { if isDirectory.boolValue { print("Skipping directory: " + filePath) }else { if let checksum = sha256Checksum(forFileAtPath: filePath) { if existing_files_checksum.contains(checksum) { print("deleting " + filePath) try fileManager.removeItem(atPath: filePath) count = count + 1 } else { print("adding " + checksum) existing_files_checksum.insert(checksum) } } else { print("Failed to calculate checksum for " + filePath) } } } } print("deleted " + String(count) + " files") It runs for hours, printing checksums. It calculates the checksum for about 17,000 files. Then my disk breaks. Here's what I mean by breaks: Before running the program:The disk checkout out with disktutil, It is fine: ls shows /volumes/16-1-23 But then, this program crashes because it can't find the next file to checksum. When I do an ls -al /volumes/16-1-23 the command returns permission denied. sudo ls -al total 0 d--x--x--x 2 root wheel 64 Apr 23 19:16 . drwxr-xr-x 23 sam wheel 736 Apr 24 09:03 .. when I do an ls /volumes I see: ls -al total 96 drwxr-xr-x 23 sam wheel 736 Apr 24 09:19 . drwxr-xr-x 20 root wheel 640 Apr 1 12:46 .. d--x--x--x 2 root wheel 64 Apr 23 19:16 16-1-23 d--x--x--x 2 root wheel 64 Apr 23 21:59 16-1-23 1 d--x--x--x 2 root wheel 64 Apr 24 04:09 16-1-23 10 d--x--x--x 2 root wheel 64 Apr 24 08:13 16-1-23 11 drwx------@ 14 sam staff 448 Apr 15 15:42 16-1-23 12 d--x--x--x 2 root wheel 64 Apr 23 22:14 16-1-23 2 d--x--x--x 2 root wheel 64 Apr 23 23:04 16-1-23 3 d--x--x--x 2 root wheel 64 Apr 23 23:04 16-1-23 4 d--x--x--x 2 root wheel 64 Apr 24 00:13 16-1-23 5 d--x--x--x 2 root wheel 64 Apr 24 00:13 16-1-23 6 d--x--x--x 2 root wheel 64 Apr 24 01:08 16-1-23 7 d--x--x--x 2 root wheel 64 Apr 24 02:01 16-1-23 8 d--x--x--x 2 root wheel 64 Apr 24 03:05 16-1-23 9 drwxrwxr-x@ 9 sam staff 288 Apr 7 13:06 16-3-23 all of the "disks" ending in a number e.g 16-1-23 9 aren't accessible. sudo ls -al 1 ↵ Password: total 0 shows: d--x--x--x 2 root wheel 64 Apr 24 03:05 . drwxr-xr-x 23 sam wheel 736 Apr 24 09:19 .. Diskuitil didn't find any errors. I'd really love to know what's going on. I can produce this error with Python code that does the same thing. I was hoping that the problem would go away if I wrote it in Swift. It didn't. I guess that's good. However, now am I really stuck. Any advice appreciated.

Here is what I am trying to do: In Python, I have a script that walks the directly the structure of internal and external local disks. If the file is an image, it copies it to a large disk. Walk directories if file is image then get a checksum for it. check a database to see if the checksum has been seen before. If yes, done (continue) if no, determine where the file should be copied to on a large 16tb disk. “/volumes/big_disk/image/date/file copy file there update database with checksum and location Here’s what’s is happening. At some point, /volumes/big_disk goes away and is replaced with something like this /volumes/big_disk 1 /volumes/big_disk 2 etc. These directories can’t be read or written to. (Permission denied error 13) game over if I reboot the computer, /volumes/big_disk 1 /volumes/big_disk 2 etc. Go away and /volumes/big_disk is back and apparently OK. Setup: M1 Mac 16 TB disk other smaller USB disks some of the smaller disks aren’t APFS the large disk is APFS Happy to upload code if that would hep. Thanks in advance !