Xcode warning "profiling: invalid magic number"

Question

I just installed Xcode 4.6. When I run my OCUnit tests now, I get multiple lines with "profiling: invalid magic number" in the output window after all tests have finished. I'm pretty sure that Xcode 4.5.2 didn't give me that output.

Does anybody know what this line means?

Answer 1

After some googling I found this LLVM source file GCDAProfiling.c

From what I can see there, the error is printed during the code coverage generation when the profiler is attempting to merge two files but one of them has a different version (= magic number).

I did a full Clean (it also removes all gcda files) and the problem went away.

Answer 2

Ended up having to delete the appropriate DerivedData folder for my application -

~/Library/Developer/Xcode/DerivedData/#application-name#

But that ended up clearing everything up.