fputs (": ", stderr);
fputs_unlocked (": ", stderr);
vwarn (const char *format, __gnuc_va_list ap){  int error = errno;  if (__progname)    fprintf (stderr, "%s: ", __progname);  if (format)    {      vfprintf (stderr, format, ap);      fputs (": ", stderr);    }  __set_errno (error);  fprintf (stderr, "%m\n");}