Scikit-learn 1.9.1 released in September 2026 with Python 3.15 support, featuring fixes for Array API classification metrics, metadata routing in meta-estimators and pipelines, callback pickling issues, and various bug fixes across clustering, datasets, discriminant analysis, and other modules.
A C# developer's progress callback wasn't being invoked during an async download operation. The root cause was that the C++/WinRT DownloadAsync method wasn't forwarding progress reports from the underlying provider operation, only awaiting and returning its result. The fix is to return the provider's IAsyncOperationWithProgress directly instead of wrapping it in a coroutine that doesn't relay progress.