Malformed or corrupted AST file

Question

I have a problem I don\'t know why did it happen in the first place but most probably because I\'ve pressed move to trash to some system frameworks by mistake.

I got an

Answer 1

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.