I have to say that I consider the whole process of developing with Xcode deeply annoying. I recently had a problem where it claimed that I needed to set a development team for signing even though I already had. After spending a lot of time deleting, recreating projects etc etc, I realized that clearly Xcode was keeping some information elsewhere that was causing the problem.
Turns out that it caches some information in:
Each project has a folder here. I deleted any folders that had the same name as my project and that fixed the problem. Ugh. And don’t get me started on bitcode…