I'm new with Juce and i'm debbuging a plugin but Xcode is breaking everywhere even if there's not a singe breakpoint.
I did not find anything oneline about that except on stackoverflow but they don't realy solve the problem. ( http://stackoverflow.com/questions/5308971/debugger-stopping-at-a-non-existent-breakpoint-in-xcode-4 )
Are you new to C/C++ as well? The image you posted shows you have stopped on an assert. asserts are a tool used development to catch things that are wrong. ie. they 'assert' what things should be, and if the condition is not met, the code breaks, so that you can see the error and fix it.