Malformed or corrupted AST file
As requested:
What caused this error for me (after getting the new Xcode) was I would try to run a project in simulator (accidentally in simulator, I never use simulator), but I'd forget to select my device or my device would become unplugged without me noticing, and it will try to run in simulator... so I would get those classic ".o" file errors... Then I would switch back to my device and get corrupt AST files...
To CURE the problem... (Follow the steps below VERY closely!!!!!)
- Clean your project
- QUIT Xcode (CMD+Q)
- Run this Terminal Command:
rm -rf ~/Library/Developer/Xcode/DerivedData/ModuleCache/* - Run this Terminal Command:
rm -rf ~/Library/Developer/Xcode/DerivedData/ModuleCache.noindex/* - Reopen Xcode
- MAKE SURE YOU HAVE YOUR DEVICE SELECTED AND NOT SIMULATOR
- CLEAN project (Yes, again)
- THEN build (to your device, not to simulator)...
Enjoy!
Note: After further experimentation I've found that the force-quitting of xCode is possibly not necessary.
In addition to all of the other "clean your build" answers, nothing was working for me until I emptied out the (highly undocumented!) /var/folders directory.
Apparently, this is a "miscellaneous caches" dir maintained by OS-X. I didn't even bother figuring out what were "the correct files"; I just cleaned out the entire directory.
...And now I can build again. Hooray! From terminal:
[sudo] rm -rf /var/folders/*
(Although I did it from Finder, via authentication.) (OS-X 10.9.latest)
Additional clue: I could build with XCode-6-beta, but got the goofy "corrupted AST file" error in XCode-5.
In my situation, all I needed to do was click Product > Clean, then build the project again. It succeeded. Hope this helps some others who run into the same situation.