code: def warn_startup_with_shell_off(platform, gdb_args):
      
      darwin_match = re.match("darwin-(\d+)\..*", platform)
      on_darwin = darwin_match is not None and int(darwin_match.groups()[0]) >= 16
      if on_darwin:
          shell_is_off = "startup-with-shell off" in gdb_args
          return not shell_is_off
      return False
docs: return True if user may need to turn shell off
      if mac OS version is 16 (sierra) or higher, may need to set shell off due
      to os's security requirements
      http://stackoverflow.com/questions/39702871/gdb-kind-of-doesnt-work-on-macos-sierra