tarunon

async/awaitにしないのはiOSのボトムの制約ですかね？

おっしゃる通りですね。iOS 14 サポートなので…backport がそろそろ来れば良いんですがまだですよね…？ https://github.com/apple/swift/pull/39051

Add an option to build the concurrency library for back deployment....

Introduce an additional build product to build-script to build back-deployable concurrency libraries. These libraries would need to be embedded in apps deployed prior to macOS 12/iOS 15 to support ...