I'm writing this because it caused me a few hours of work today. I figured it out so now maybe somebody else won't waste any time.
I'm an iOS developer and I use AppCode instead of Xcode.
I'm in the process of trying to update our app using Swift's new concurrency features. We use Alamofire for REST stuff.
The problem:
Trying to use Alamofire's concurrency methods in AppCode don't show up as valid methods. The IDE/Compiler didn't recognize the methods.
In my case, it was .serializingString()
.