rem: static char str[80]; struct tm *tm = localtime (t);
add: static char str[MAX (INT_BUFSIZE_BOUND (intmax_t), (INT_STRLEN_BOUND (int)  + 1  + sizeof "-MM-DD HH:MM:SS.NNNNNNNNN +ZZZZ"))]; struct tm const *tm = localtime (&t);
context: human_time (time_t const *t){  static char str[80];  struct tm *tm = localtime (t);  if (tm == NULL)    {      G_fail = 1;      return (char *) _("*** invalid date/time ***");    }  nstrftime (str, sizeof str, "%Y-%m-%d %H:%M:%S.%N %z", tm, 0, 0);  return str;}