`useBackgroundSession: true` caused downloads to hang after a few %

[iandundas]

WhisperKit 0.11.0

Reproducible by setting useBackgroundSession: true on WhisperKit.download(..).

It reliably freezes like this:

Possibly there is further configuration needed to get background downloads working which would unblock this, I'm not sure.

[ZachNagengast]

Background sessions on mac have been problematic in the past with swift-transformers, generally only recommended for iOS since the concept of "background session" works slightly differently for mac. According to apple's docs, if you declare the right background modes, you can skip using the background session entirely and it will behave the same way https://developer.apple.com/documentation/foundation/downloading-files-in-the-background

Note
You don’t have to do all background network activity with background sessions as described in this article. Apps that declare >appropriate background modes can use default URL sessions and data tasks, just as if they were in the foreground.

[iandundas]

Sorry, I wasn't clear: I reproduced it on macOS by way of showing it in the example project, but before that I was seeing the same in our iOS app

[wooster]

@ZachNagengast I think that part of the docs is referring to using normal URL sessions within the context of background tasks. https://developer.apple.com/documentation/uikit/using-background-tasks-to-update-your-app