问题
I am developing an app with Swift and I started to experience a strange Xcode behaviour at some point. I do not exactly remember how it happened, but the autocomplete is refusing to work and for all of my variables the type is << error type >> . I tried some of the solutions available here, but all of them did not work. What could be the issue for this frustrating behaviour, please share your thoughts if you have already experienced this problem and solved it. I already deleted the derived data and checked if some of my paths are not correct, but everything seems fine.
回答1:
I was about to give up and work without the autocomplete feature, I even reinstalled XCode but with no success. What I forgot to try was to delete the .xcuserdatad folder that can be found when you right click on the project and select the Show Package Contents, then open xcuserdata folder and delete the [Username].xcuserdatad folder. It worked like a charm, the autocomplete is "alive" again and XCode works better than ever before. I hope this would help anyone with the same annoying issue...
来源：https://stackoverflow.com/questions/26717126/xcode-6-autocomplete-failure-error-type