"Slow" background tasks never start

[g123k]

Hi everyone (and more specifically @monsieurtanuki)!

I have an issue on my phone with 19 "slow background tasks".
The first one (not visible in the screenshot) was always in error, so I deleted it.

Now I have 18 slow tasks and they never start.
On screen changes, "fast" & "longHaul" are checked, but not "slow"-ed ones.
Is there any reason?

[g123k]

The faulty task is removed, but there's still this error 🤨

BackgroundTaskManager:	 Background task error
PathNotFoundException: Cannot open file, path = '/var/mobile/Containers/Data/Application/D04F519F-A039-48F0-89C0-AB8B6381E1F6/Library/Application Support/full_image_382.jpeg.cropped.jpg' (OS Error: No such file or directory, errno = 2)

Seems similar to #6283

[monsieurtanuki]

Seems similar to #6283

Indeed. Could it be that our "friends" of apple changed again the location of their standard dirs?
A solution might be to store files in the database, in order to avoid that kind of jokes.

[monsieurtanuki]

@g123k For the record this is what we already do about file dirs on iOS:

  static Future<Directory> getDirectory() async =>
      getApplicationSupportDirectory();

  /// Returns a "safe" [File] from a given [path].
  ///
  /// iOS sometimes changes the path of its standard app folders, like the one
  /// we use in [getDirectory].
  /// With this method we refresh the path for iOS.
  /// cf. https://github.com/openfoodfacts/smooth-app/issues/4725
  static Future<File> getFile(String path) async {
    if (Platform.isIOS) {
      final int lastSeparator = path.lastIndexOf('/');
      final String filename =
          lastSeparator == -1 ? path : path.substring(lastSeparator + 1);
      final Directory directory = await getDirectory();
      path = '${directory.path}/$filename';
    }
    return File(path);
  }

As you are fortunate enough to experience the bug, would you try to check if the named dir (/var/mobile/Containers/Data/Application/D04F519F-A039-48F0-89C0-AB8B6381E1F6/Library/Application Support/) does exist?

[g123k]

Seems similar to #6283

Indeed. Could it be that our "friends" of apple changed again the location of their standard dirs? A solution might be to store files in the database, in order to avoid that kind of jokes.

It seems that files are lost when we relaunch the app (I've reproduced the issue).
Just to be sure: in the code, you never delete files on boot?

[monsieurtanuki]

It seems that files are lost when we relaunch the app (I've reproduced the issue).

That would be an undesired new behavior.
You mean relaunch, no reinstall, right?

Just to be sure: in the code, you never delete files on boot?

I wouldn't see the point.

[g123k]

Quick demo: the photo is gone when the app is restarted:
https://github.com/user-attachments/assets/28c8d5b3-f052-41a6-9829-87fbff421eed

The photo indicator is also displayed indefinitely.

[monsieurtanuki]

@g123k Unfortunately I cannot watch your video.
You're in the best position to fix the bug as you can reproduce it.