I am using Xcode 5 but this would happen to me when using Xcode 4 as well.
It seems that for fairly large projects with lots of files, Xcode doesn't track issues very well. By "issues" I mean the "!-in-red-octagon" symbol that pops up next to lines where there are issues that will prevent Xcode from building your app. Oftentimes it seems that a single issue will prevent tracking of other issues within the same method. Other times it seems Xcode accepts method calls that do not actually exist or that have been commented out (i.e., where it should throw an error). And in other methods all issues are recognized and tracked correctly. I unfortunately can't figure out what seems to cause identical issues to be recognized in one place but not the other.
QUESTION: Is this (buggy?) behavior something I can correct? If yes, then how do I get Xcode to show the !-in-red-octagon warning for all issues and not just (randomly?) selected issues?
Cleaning the project (Shift-Cmd-K) doesn't seem to help, as the same issues are still highlighted and the same issues are ignored. Likewise, attempting to build and failing end with similar results. New issues are only highlighted once the already-highlighted issues are resolved and I attempt to build again.
Since my current project is fairly large, live issue tracking is incredibly helpful. E.g., I've used it to comment out a method so that I can trace what other methods are calling that method in order to make sure that it is being used in the right places. Perhaps this is bad practice but it is incredibly helpful as I have a bad working memory.
This question may or may not a duplicate of the following question, as I'm not sure what the correct term for "!-in-red-octagon" is: In Xcode 4.5 "Show Live Issues" no longer works