title: Xcode 4 / Cannot understand why some symbols are missing when debugging
body: <p>I recently switched to Xcode 4 and the debug process is confusing. I read the Xcode manual but still cannot understand why some symbols cannot be displayed by gdb when putting the pointer onto it in the editor or when doing "po xxxxxx" where xxxx is the symbol name. I get the message "Unable to access variable" in an infinite loop.</p>
  
  <p>This looks like some debug symbols have been removed (as if I was in release instead of debug but those concepts disappeared from Xcode). Is there something I should activate in order to have these symbols available ?</p>
  
  <p>Regards,
  Franz</p>