Xcode fails without specifying and errors

Question

All of a sudden my project fails to build in Xcode. If I look at the log I see all the needed dependencies being built, and then I get a strange error:

Verify fi         


        

Answer 1

Build operation failed without specifying any errors. Individual build tasks may have failed for unknown reasons. One possible cause is if there are too many (possibly zombie) processes; in this case, rebooting may fix the problem. Some individual build task failures (up to 12) may be listed below.

I've run into this problem consistently recently while running Xcode 9.0 Beta 3 and Xcode 8.3.3.

The fix is to delete ALL in the Derived Data folder. It then seems to work again.

rm -rf ~/Library/Developer/Xcode/DerivedData

NOTE: just cleaning the build or deleting the current build folder for a project does not seem to help.

Hope this helps :)