Prevent Xcode from building if there are warnings

Question

I want my Xcode project to have no warnings. How can I configure Xcode such that it won't build as long as there are warnings?

Answer 1

set treat warnings as errors = YES in the build settings

Answer 2

You can add the -Werr switch to the compiler flags (on the Build phases tab, if I recall correctly). This will make the compiler treat all warnings as errors and it will choke on each warning.