问题
I had a Mac app that I've been working on for almost two years now that suddenly decided it wouldn't run on either of my computers (which have their projects synced via Dropbox.) It was building and archiving fine, but I couldn't start it with a debugger or run unit tests on it.
Every time I tried it would give an error, either:
< My App Name > exited unexpectedly
lost connection
or something about having lost connection and timed out (I didn't copy down exactly what the error message was, and now I can't get it to appear again.)
I tried using another computer, I tried restarting Xcode, and restarting OS X. Everything I found through Google or on Stack Overflow just didn't help me. I created a new project and found I could run it and unit tests on it fine, so I'm pretty certain the issue lies somewhere within my project.
回答1:
I was about to try reinstalling Xcode or OS X or just making a new blank project and copying stuff over when I remembered one other option, which worked like a charm.
(In Mac Menu Bar) > Product > Clean
⇧ (shift)+⌘ (command)+K
来源：https://stackoverflow.com/questions/19720658/xcode-5-builds-and-archives-but-wont-run-or-test-mac-apps