How to get the Quick Help back in Xcode 10?

Question

After I upgraded to Xcode 10 the Quick Help information only provide declaration of the selected class or structure.

Is there a setting somewhere that I can make it same as what it was in Xcode 9?

Answer 1

I had the same issue after upgrading where the function signature is the only thing showing when doing an option click. Quick Help reappeared when I deleted everything inside ~/Library/Developer/Xcode/DerivedData as well as in ~/Library/Caches/com.apple.dt.Xcode. You need to quit xcode first btw. Hope this helps.