_thread_printf
_thread_printf(STDERR_FILENO, "Fatal error '");
_thread_printf(STDERR_FILENO, "' at line %d in file %s (errno = %d)\n",
_thread_printf(2, "Warning: old _pthread_cleanup_push was called, "
void _thread_printf(int, const char *, ...) __hidden __printflike(2, 3);
#define stdout_debug(args...) _thread_printf(STDOUT_FILENO, ##args)
#define stderr_debug(args...) _thread_printf(STDERR_FILENO, ##args)